From seminars-announce.astro-at-su.se at lists.su.se Mon Jan 9 16:02:25 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 9 Jan 2023 16:02:25 +0100 Subject: [Astronomy seminar] Astronomy departmental seminar this Friday Jan 13th with Emir Karamehmetoglu Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday January 13th at 10:30 in room FC 61 (AlbaNova building, 6th floor) and on zoom. ———————————————————————————————————————————————————————————————— Speaker: Emir Karamehmetoglu Title: Explosive hide and seek with massive stars Abstract: The observational study of supernovae is undergoing a revolution brought about by an abundance of high quality data. The rich dataset offers insights into one of the biggest mysteries in the field; what are the ultimate fates of massive of stars? Interestingly, both theoretical and observational research suggests a lack of SNe associated with the most massive of stars. Is this real, or are they hiding in the data? I will present my PhD thesis work investigating the apparent mystery of the missing massive stars, by focusing on stripped-envelope (SE) supernovae (SNe), which are thought to have high-mass origins. I will present two types of rare SE SN sub-types which could be the hiding spots: interacting Type Ibn and broad lightcurve SE SNe. Finally, I will present our systematic search that discovered an under-appreicated population of the latter, which are strongly associated to extremely high-mass SE SNe and potentially to high-mass stars. ———————————————————————————————————————————————————————————————— https://www.albanova.se/event/explosive-hide-and-seek-with-massive-stars/ We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-01-20 Smaranika Bannerjee (SU) 2023-01-27 No seminar 2023-02-03 Kelley Hess (IAA - Granada, Spain) ———————————————————————————————————————————————————————————————— Topic: Astronomy Department Seminar Fernanda Nieva Time: Jan 13th, 2023 10:30 AM Stockholm Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Launch Meeting - Zoom stockholmuniversity.zoom.us Zoom is the leader in modern enterprise video communications, with an easy, reliable cloud platform for video and audio conferencing, chat, and webinars across mobile, desktop, and room systems. Zoom Rooms is the original software-based conference room solution used around the world in board, conference, huddle, and training rooms, as well as executive offices and classrooms. Founded in 2011, Zoom helps businesses and organizations bring their teams together in a frictionless environment to get more done. Zoom is a publicly traded company headquartered in San Jose, CA. Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Jan 13 10:22:29 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 13 Jan 2023 10:22:29 +0100 Subject: [Astronomy seminar] Astronomy departmental seminar this Friday Jan 13th with Emir Karamehmetoglu In-Reply-To: <7BCB3683-3854-48F1-82AD-CA92EABCCDAD@astro.su.se> References: <7BCB3683-3854-48F1-82AD-CA92EABCCDAD@astro.su.se> Message-ID: Reminder about Emir’s seminar in 10 minutes! Kind regards, Eliot > On 9 Jan 2023, at 16:02, Eliot Ayache wrote: > > Dear all, > > The next SU astronomy departmental seminar will take place on Friday January 13th at 10:30 in room FC 61 (AlbaNova building, 6th floor) and on zoom. > > ———————————————————————————————————————————————————————————————— > > Speaker: Emir Karamehmetoglu > Title: Explosive hide and seek with massive stars > > Abstract: > > The observational study of supernovae is undergoing a revolution brought about by an abundance of high quality data. The rich dataset offers insights into one of the biggest mysteries in the field; what are the ultimate fates of massive of stars? Interestingly, both theoretical and observational research suggests a lack of SNe associated with the most massive of stars. Is this real, or are they hiding in the data? > > I will present my PhD thesis work investigating the apparent mystery of the missing massive stars, by focusing on stripped-envelope (SE) supernovae (SNe), which are thought to have high-mass origins. I will present two types of rare SE SN sub-types which could be the hiding spots: interacting Type Ibn and broad lightcurve SE SNe. Finally, I will present our systematic search that discovered an under-appreicated population of the latter, which are strongly associated to extremely high-mass SE SNe and potentially to high-mass stars. > > ———————————————————————————————————————————————————————————————— > > https://www.albanova.se/event/explosive-hide-and-seek-with-massive-stars/ > > We look forward to seeing many of you there. Thanks! > > Eliot and Kris > > > > Upcoming Events: > > 2023-01-20 Smaranika Bannerjee (SU) > 2023-01-27 No seminar > 2023-02-03 Kelley Hess (IAA - Granada, Spain) > > ———————————————————————————————————————————————————————————————— > > Topic: Astronomy Department Seminar Fernanda Nieva > Time: Jan 13th, 2023 10:30 AM Stockholm > > Join Zoom Meeting: > https://stockholmuniversity.zoom.us/s/61002076352 > Launch Meeting - Zoom > stockholmuniversity.zoom.us > Zoom is the leader in modern enterprise video communications, with an easy, reliable cloud platform for video and audio conferencing, chat, and webinars across mobile, desktop, and room systems. Zoom Rooms is the original software-based conference room solution used around the world in board, conference, huddle, and training rooms, as well as executive offices and classrooms. Founded in 2011, Zoom helps businesses and organizations bring their teams together in a frictionless environment to get more done. Zoom is a publicly traded company headquartered in San Jose, CA. > > > Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Tue Jan 17 09:58:08 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Tue, 17 Jan 2023 09:58:08 +0100 Subject: [Astronomy seminar] Astro Department Seminar - Fri Jan 20th 10:30 - Smaranika Banerjee Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday January 20th at 10:30 in room FC 61 (AlbaNova building, 6th floor) and on zoom. ——————————— Speaker: Smaranika Banerjee Title: Early kilonova from neutron star merger https://www.albanova.se/event/early-kilonova-from-neutron-star-merger/ Abstract: In binary neutron star (BNS) mergers, the radioactive decay of freshly synthesized heavy elements produces emissions in the ultraviolet-optical-infrared range, giving rise to a transient called a kilonova. The kilonova is an excellent probe to understand the origin of elements heavier than iron. The observational properties of the kilonova (light curve and spectra) depend on the bound-bound opacity of the heavy elements. Hence, a detailed opacity is necessary to model the realistic kilonova light curve and spectra. However, such calculations for opacity, and correspondingly, the realistic light curve, were largely unavailable, especially for the condition suitable at an early time (t < 1 day). In my talk, I will discuss recent developments and challenges in modelling kilonova light curves. Also, I will share my recent work on opacity and light curve calculations of the kilonova, focusing on early time (t < 1 day). ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-01-27 Mingjie Jian (SU) 2023-02-03 Kelley Hess (IAA - Granada, Spain) 2023-02-10 No seminar - OKC day 2023-02-17 Diane Feuillet (Lund Obs.) ——————————— Topic: Astronomy Department Seminar Smaranika Banerjee Time: Jan 20th, 2023 10:30 AM Stockholm Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Jan 20 10:20:29 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 20 Jan 2023 10:20:29 +0100 Subject: [Astronomy seminar] Astro Department Seminar - Fri Jan 20th 10:30 - Smaranika Banerjee In-Reply-To: References: Message-ID: Hi all, friendly reminder about Smaranika’s seminar in 10 minutes! See you all there, Best, Eliot > On 17 Jan 2023, at 09:58, Eliot Ayache wrote: > > Dear all, > > The next SU astronomy departmental seminar will take place on Friday January 20th at 10:30 in room FC 61 (AlbaNova building, 6th floor) and on zoom. > > ——————————— > Speaker: Smaranika Banerjee > Title: Early kilonova from neutron star merger > https://www.albanova.se/event/early-kilonova-from-neutron-star-merger/ > > Abstract: > In binary neutron star (BNS) mergers, the radioactive decay of freshly synthesized heavy elements produces emissions in the ultraviolet-optical-infrared range, giving rise to a transient called a kilonova. The kilonova is an excellent probe to understand the origin of elements heavier than iron. The observational properties of the kilonova (light curve and spectra) depend on the bound-bound opacity of the heavy elements. Hence, a detailed opacity is necessary to model the realistic kilonova light curve and spectra. However, such calculations for opacity, and correspondingly, the realistic light curve, were largely unavailable, especially for the condition suitable at an early time (t < 1 day). > In my talk, I will discuss recent developments and challenges in modelling kilonova light curves. Also, I will share my recent work on opacity and light curve calculations of the kilonova, focusing on early time (t < 1 day). > ——————————— > > We look forward to seeing many of you there. Thanks! > > Eliot and Kris > > > > Upcoming Events: > > 2023-01-27 Mingjie Jian (SU) > 2023-02-03 Kelley Hess (IAA - Granada, Spain) > 2023-02-10 No seminar - OKC day > 2023-02-17 Diane Feuillet (Lund Obs.) > > > ——————————— > Topic: Astronomy Department Seminar Smaranika Banerjee > Time: Jan 20th, 2023 10:30 AM Stockholm > > Join Zoom Meeting: > https://stockholmuniversity.zoom.us/s/61002076352 > Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Jan 20 16:34:00 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 20 Jan 2023 16:34:00 +0100 Subject: [Astronomy seminar] Astro Department Seminar - Hybrid setup questionnaire In-Reply-To: <6A2D2916-AF6D-483F-8602-55938CBEAD82@astro.su.se> References: <6A2D2916-AF6D-483F-8602-55938CBEAD82@astro.su.se> Message-ID: Hi all, First of all, thank you for attending the SU department seminars regularly. We’ve had some very interesting discussion so far this academic year! We’d like to hear your thoughts on the current hybrid setup that we have. Please take 1 minute to fill up the google form anonymously. (Note that whether we keep the zoom setup, or can argue for hardware upgrades will depend on the engagement we receive) https://docs.google.com/forms/d/e/1FAIpQLScGYSqRb3lpnsAxA0uGw5CzolVG-wR7bPemqN1wCZgTXmMf5A/viewform?usp=sf_link Thanks! Kind regards, Eliot and Kris > On 20 Jan 2023, at 10:20, Eliot Ayache wrote: > > Hi all, > > friendly reminder about Smaranika’s seminar in 10 minutes! > > See you all there, > > Best, > Eliot > >> On 17 Jan 2023, at 09:58, Eliot Ayache > wrote: >> >> Dear all, >> >> The next SU astronomy departmental seminar will take place on Friday January 20th at 10:30 in room FC 61 (AlbaNova building, 6th floor) and on zoom. >> >> ——————————— >> Speaker: Smaranika Banerjee >> Title: Early kilonova from neutron star merger >> https://www.albanova.se/event/early-kilonova-from-neutron-star-merger/ >> >> Abstract: >> In binary neutron star (BNS) mergers, the radioactive decay of freshly synthesized heavy elements produces emissions in the ultraviolet-optical-infrared range, giving rise to a transient called a kilonova. The kilonova is an excellent probe to understand the origin of elements heavier than iron. The observational properties of the kilonova (light curve and spectra) depend on the bound-bound opacity of the heavy elements. Hence, a detailed opacity is necessary to model the realistic kilonova light curve and spectra. However, such calculations for opacity, and correspondingly, the realistic light curve, were largely unavailable, especially for the condition suitable at an early time (t < 1 day). >> In my talk, I will discuss recent developments and challenges in modelling kilonova light curves. Also, I will share my recent work on opacity and light curve calculations of the kilonova, focusing on early time (t < 1 day). >> ——————————— >> >> We look forward to seeing many of you there. Thanks! >> >> Eliot and Kris >> >> >> >> Upcoming Events: >> >> 2023-01-27 Mingjie Jian (SU) >> 2023-02-03 Kelley Hess (IAA - Granada, Spain) >> 2023-02-10 No seminar - OKC day >> 2023-02-17 Diane Feuillet (Lund Obs.) >> >> >> ——————————— >> Topic: Astronomy Department Seminar Smaranika Banerjee >> Time: Jan 20th, 2023 10:30 AM Stockholm >> >> Join Zoom Meeting: >> https://stockholmuniversity.zoom.us/s/61002076352 >> Meeting ID: 610 0207 6352 > -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Jan 23 16:07:44 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 23 Jan 2023 15:07:44 +0000 Subject: [Astronomy seminar] SU astronomy departmental seminar Friday January 27th - Mingjie Jian Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday January 27th at 10:30 in room FC 61 (AlbaNova building, 6th floor) and on zoom. ——————————— Speaker: Mingjie Jian (SU) Title: The behavior of the chromospheric lines of helium at 10830Å in late-type stars https://www.albanova.se/event/astronomy-departmental-seminar-mingjie-jian-su/ Abstract: The stellar helium abundance is an essential parameter which is expected to provide important clues on the chemical evolution of our Milky Way. It is believed to be enhanced in the second (and later) generation(s) in globular clusters and one of the double red clump, though the latter is still under intense debate. However, it is hard to determine the helium abundance of late-typed star spectroscopically. Previous studies have shown that the chromospheric helium line at 10830 Å (He 10830) has the potential to be used as a helium abundance indicator, but observations of this line have been insufficient. We collected a large sample of medium- and high-resolution spectra covering the wavelength range of He 10830 for over 700 stars. We found systemic trends between line strength and other parameters, and that the photoionization-recombination formation mechanism dominates in the dwarfs and warm giants. Thus He 10830 is difficult to use as a helium abundance tracer for these stars. The cool giants, on the other hand, are expected to have weak or no corona, thus still having the possibility to trace their helium abundance using He 10830. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-02-03 Kelley Hess (IAA - Granada, Spain) 2023-02-10 No seminar - OKC day 2023-02-17 Diane Feuillet (Lund Obs.) 2023-02-24 Martin Rey (Oxford) ——————————— Topic: Astronomy Department Seminar Mingjie Jian Time: Jan 27th, 2023 10:30 AM Stockholm Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Jan 30 15:23:52 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 30 Jan 2023 15:23:52 +0100 Subject: [Astronomy seminar] Astro Department Seminar - Fri Feb 3rd 10:30 - Kelley Hess (IAA-CSIC, Granada) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday February 3rd at 10:30 in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352 ). ——————————— Speaker: Kelley Hess (IAA-CSIC, Granada, Spain) Title: Ram pressure stripping in galaxy cluster substructure https://www.albanova.se/event/astronomy-departmental-seminar-kelley-hess-csic/ Abstract: In the cluster environment, a galaxy’s motion through the ICM results in a loss of the multi-phase interstellar medium through ram pressure stripping. This can be seen through the displacement of neutral and ionized gas, and triggered star formation. To date, the impact of ram pressure has been considered almost exclusively from the stand point of individual galaxies. However, a large fraction of cluster members have been accreted as members of groups, which contain their own warm/hot intragroup medium. We present a multi-wavelength study including exquisite MeerKAT HI and DECam Halpha imaging of the center of the Hydra Cluster and a foreground galaxy group. Members of the group exhibit compressed HI contours, well-defined HI tails, and ongoing star formation in the stripped gas. We use the HI and stellar morphologies, combined with a Beta model of the hot ICM, to constrain the galaxy orbits and real distances of the galaxies to the cluster center. It’s likely that the group has already passed its pericenter and is actually on “out fall” from the cluster. The high surviving HI content of the galaxies may suggest that the substructure/intragroup medium or CGM can protect them from the harshest effects of ram pressure, or that the galaxies are on more tangential orbits. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-02-10 No seminar - OKC day 2023-02-17 Diane Feuillet (Lund Obs.) 2023-02-24 Martin Rey (Oxford Uni., UK) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Feb 3 10:09:04 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 3 Feb 2023 10:09:04 +0100 Subject: [Astronomy seminar] Astro Department Seminar - Fri Feb 3rd 10:30 - Kelley Hess (IAA-CSIC, Granada) In-Reply-To: <2CF5E6F5-0B21-46D6-A8D3-4587750A3D6C@astro.su.se> References: <2CF5E6F5-0B21-46D6-A8D3-4587750A3D6C@astro.su.se> Message-ID: Dear all, This is a reminder about Kelley Hess’s seminar in 20 minutes! Kind regards, Eliot > On 30 Jan 2023, at 15:23, Eliot Ayache wrote: > > Dear all, > > The next SU astronomy departmental seminar will take place on Friday February 3rd at 10:30 in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352 ). > > ——————————— > Speaker: Kelley Hess (IAA-CSIC, Granada, Spain) > Title: Ram pressure stripping in galaxy cluster substructure > https://www.albanova.se/event/astronomy-departmental-seminar-kelley-hess-csic/ > > Abstract: > In the cluster environment, a galaxy’s motion through the ICM results in a loss of the multi-phase interstellar medium through ram pressure stripping. This can be seen through the displacement of neutral and ionized gas, and triggered star formation. To date, the impact of ram pressure has been considered almost exclusively from the stand point of individual galaxies. However, a large fraction of cluster members have been accreted as members of groups, which contain their own warm/hot intragroup medium. We present a multi-wavelength study including exquisite MeerKAT HI and DECam Halpha imaging of the center of the Hydra Cluster and a foreground galaxy group. Members of the group exhibit compressed HI contours, well-defined HI tails, and ongoing star formation in the stripped gas. We use the HI and stellar morphologies, combined with a Beta model of the hot ICM, to constrain the galaxy orbits and real distances of the galaxies to the cluster center. It’s likely that the group has already passed its pericenter and is actually on “out fall” from the cluster. The high surviving HI content of the galaxies may suggest that the substructure/intragroup medium or CGM can protect them from the harshest effects of ram pressure, or that the galaxies are on more tangential orbits. > ——————————— > > We look forward to seeing many of you there. Thanks! > > Eliot and Kris > > > > Upcoming Events: > > 2023-02-10 No seminar - OKC day > 2023-02-17 Diane Feuillet (Lund Obs.) > 2023-02-24 Martin Rey (Oxford Uni., UK) > > > ——————————— > Join Zoom Meeting: > https://stockholmuniversity.zoom.us/s/61002076352 > Meeting ID: 610 0207 6352 > -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Tue Feb 14 08:57:34 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Tue, 14 Feb 2023 08:57:34 +0100 Subject: [Astronomy seminar] Astro Department Seminar - Fri Feb 17th 10:30 - Diane Feuillet (Lund observatory) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday February 17th at 10:30 in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352 ). ——————————— Speaker: Diane Feuillet (Lund Observatory) Title: Characterizing epochs of star formation across the Milky Way disc using age-metallicity distributions of GALAH stars https://www.albanova.se/event/astronomy-departmental-seminar-diane-feuillet/ Abstract: The age-metallicity relation of a galaxy is predicted to reflect its star formation history, providing significant insight into the galaxy’s evolution. However, the observed age-metallicity relation of the Milky Way disk has historically been confusingly featureless, showing little correlation between the age and metallicity of stars. Recently, larger datasets and new statistical analysis methods have revealed significant detail and complexity in the age-metallicity relation of the Milky Way disk. We present a detailed map of the ages and metallicities of turn-off stars in the Milky Way disk based on data from GALAH DR3 and Gaia EDR3. From this map, we identify previously undetected features in the age-metallicity distribution of disc stars and interpret these results as indicating a three-phase formation history of the Milky Way. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-02-24 Martin Rey (Oxford Uni., UK) 2023-03-03 No Seminar (Sportlov) 2023-03-10 Ryan Boukrouche (SU) The calendar for later planned seminars is available here . (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Feb 17 10:11:28 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 17 Feb 2023 10:11:28 +0100 Subject: [Astronomy seminar] Astro Department Seminar - Fri Feb 17th 10:30 - Diane Feuillet (Lund observatory) In-Reply-To: References: Message-ID: Dear all, This is a friendly reminder about Diane’s seminar in 20 minutes in FC61 and on zoom (https://stockholmuniversity.zoom.us/s/61002076352 ). We hope to see many of you there! Best, Eliot and Kris > On 14 Feb 2023, at 08:57, Eliot Ayache wrote: > > Dear all, > > The next SU astronomy departmental seminar will take place on Friday February 17th at 10:30 in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352 ). > > ——————————— > Speaker: Diane Feuillet (Lund Observatory) > Title: Characterizing epochs of star formation across the Milky Way disc using age-metallicity distributions of GALAH stars > https://www.albanova.se/event/astronomy-departmental-seminar-diane-feuillet/ > > Abstract: > The age-metallicity relation of a galaxy is predicted to reflect its star formation history, providing significant insight into the galaxy’s evolution. However, the observed age-metallicity relation of the Milky Way disk has historically been confusingly featureless, showing little correlation between the age and metallicity of stars. Recently, larger datasets and new statistical analysis methods have revealed significant detail and complexity in the age-metallicity relation of the Milky Way disk. We present a detailed map of the ages and metallicities of turn-off stars in the Milky Way disk based on data from GALAH DR3 and Gaia EDR3. From this map, we identify previously undetected features in the age-metallicity distribution of disc stars and interpret these results as indicating a three-phase formation history of the Milky Way. > ——————————— > > We look forward to seeing many of you there. Thanks! > > Eliot and Kris > > > Upcoming Events: > > 2023-02-24 Martin Rey (Oxford Uni., UK) > 2023-03-03 No Seminar (Sportlov) > 2023-03-10 Ryan Boukrouche (SU) > > The calendar for later planned seminars is available here . > (Please note that calendar can be subject to updates) > > ——————————— > Join Zoom Meeting: > https://stockholmuniversity.zoom.us/s/61002076352 > Meeting ID: 610 0207 6352 > -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Feb 20 15:56:21 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 20 Feb 2023 14:56:21 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday February 24th - Martin Rey (Oxford) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday February 24th at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ——————————— Speaker: Martin Rey (Oxford) Title: Insights into the faint and diffuse universe of galaxies https://www.albanova.se/event/astronomy-department-seminar-martin-rey-oxford/ Abstract: Recent advances have transformed our understanding of galaxies at the low surface brightness frontier. New imaging capabilities have unveiled a new population of ever smaller "ultra-faint" dwarf galaxies, while astrometric measurements from the GAIA mission is revealing a growing number of chemo-dynamical structures in the diffuse outskirts of our Milky Way. Such low-mass, feeble objects are highly sensitive to the physical processes that shape the cosmological growth of galaxies in our Universe, providing an ideal laboratory for testing galaxy formation models and the nature of dark matter. This same sensitivity, however, also generates extended scatter in their properties and uncertainties in model predictions, making their interpretation challenging. I will showcase results from the new approach of "genetically modified" cosmological simulations of galaxies, allowing us to uniquely separate the role of cosmological assemblies and physical models in a galaxy's final observables. I will show how this unique combination of abilities enables us to extract the expected diversity in the stellar and gaseous properties of the faintest galaxies in our Universe and make testable predictions for near-future photometric and radio surveys. I will then show how this approach can provide novel and original insights into the formation of our Milky Way, opening a new pathway to interpret Galactic observations and to constrain the formation of our Galaxy in a fully cosmological context. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-03-03 No Seminar (Sportlov) 2023-03-10 Ryan Boukrouche (SU) 2023-03-17 Mansi Kasliwal (Caltech) - Zoom only The calendar for later planned seminars is available here. (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Mar 6 13:06:35 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 6 Mar 2023 12:06:35 +0000 Subject: [Astronomy seminar] SU astronomy departmental seminar Friday March 10th - Ryan Boukrouche (SU) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday, March 10th at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ——————————— Speaker: Ryan Boukrouche (SU) Title: Transition to the post-runaway climate state on rocky worlds with large surface water inventories. https://www.albanova.se/event/astronomy-departmental-seminar-ryan-boukrouche-su/ Abstract: The lifetime of habitability on rocky planets orbiting stars that brighten over time, like the Sun, is finite. Once the planet finds itself closer to its star than the inner edge of its habitable zone, any ocean of liquid water on its surface evaporates, and the atmosphere goes into a temporary water-rich phase if enough water was initially present. After millions of years, the planet eventually loses its water. This is the runaway greenhouse effect, the ultimate climate catastrophe that turns potentially temperate planets into hot wastelands with a steam atmosphere overlying a possibly molten magma surface. The advent of the James Webb Space Telescope and the promise of future observatories makes studying these prime examples of failed Earths all the more timely. I will introduce the field of exoplanet climate modelling in the context of a study that focused on modelling the different ways that such a planet can stop heating up and start cooling down to transition to a post-runaway climate state. I explore the properties that its atmosphere would feature, including the location of potential clouds that could improve or hamper habitability prospects. I also estimate what the JWST could see when observing such planets, assuming that their climate is undergoing the processes that we are modelling. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-03-17 Mansi Kasliwal (Caltech) - Zoom only (talk at 3pm) 2023-03-24 Priscila Pessi (SU) 2023-03-31 Mattia Sirressi (SU) 2023-04-7 No Seminar - Långfredagen The calendar for later planned seminars is available here. (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Thu Mar 16 12:15:08 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Thu, 16 Mar 2023 11:15:08 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday March 17 at 3pm Message-ID: Dear all, The next SU astronomy departmental seminar will take place Tomorrow, Friday, March 17th at 15:00 in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). The talk will be given remotely and it will take place in the afternoon (3pm - please note the different time), given that the speaker will be joining us from California. For those who are at Albanova, we will be showing the talk in FC 61 on the screen, so you are welcome to attend in person for a more lively atmosphere. Fika will be shifted to accommodate/compliment the talk. ——————————— Speaker: Mansi Kasliwal (Caltech) Title: Unveiling Our Dynamic Infrared Sky. https://www.albanova.se/event/astronomy-departmental-seminar-mansi-kasliwal-caltech/ Abstract: Our Universe has many stellar outcomes that shine the brightest in the infrared due to atomic opacity, self enshrouding, dust extinction, or low temperature. Multi-messenger emission from neutron star mergers is ubiquitous in the infrared as the bound-bound opacity of heavy elements pushes the peak of the emission to redder wavelengths. Emission from massive stars experiencing copious mass-loss or merging with other stars is self-obscured and better studied in the infrared. White dwarf merger products show dimming events that are best detected in the infrared. A classical nova or a Galactic supernova deep in the disk of the Milky Way is also likely brightest in the infrared on account of line-of-sight extinction. Yet, the infrared time-domain is hitherto largely unexplored. In this colloquium, I describe how I am starting to open up the dynamic infrared sky with a series of experiments. First, I will describe a pathfinder SPIRITS survey with the Spitzer Space Telescope. Next, I will present the first wide-field infrared surveyor, Palomar Gattini IR, that is mapping 15000 square degrees to a J-band depth of 16 mag every two nights. Looking ahead, I will conclude with plans for the next generation infrared surveyors: WINTER at Palomar Observatory in California, DREAMS in Australia, PRIME in South Africa and Cryoscope in Antarctica. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-03-24 Priscila Pessi (SU) 2023-03-31 Mattia Sirressi (SU) 2023-04-7 No Seminar - Långfredagen The calendar for later planned seminars is available here. (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Tue Mar 21 10:49:43 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Tue, 21 Mar 2023 10:49:43 +0100 Subject: [Astronomy seminar] Astro Department Seminar - Fri Jan 20th 10:30 - Smaranika Banerjee In-Reply-To: References: Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday March 24th at 10:30 in room FC 61 (AlbaNova building, 6th floor) and on zoom. ——————————— Speaker: Priscila Pessi (SU) Title: Connecting observed properties of supernovae to progenitor scenarios https://www.albanova.se/event/astronomy-departmental-seminar-priscila-pessi-su/ Abstract: Supernovae (SNe) mark the explosive death of certain groups of stars. Theoretical models that take into account stellar evolution of predefined progenitor stars propose different explosion mechanisms. However, it is still not clear how the variation of characteristics such as metallicity, mass loss rate and multiplicity – among others – impact on the observed properties of SNe. Even when some models have been supported by observations, the scarcity of direct detections of progenitor stars prevents us from understanding the exact nature of the stars that explode as different types of SNe. In this talk I will present the observational analysis of three different SNe samples done during my PhD. The goal of the analysis is to associate observed characteristics to progenitor properties. The first studied sample consists of the light curves of 73 type II SNe from the Carnegie Supernova Project (CSP) and 21 type IIb SNe from the literature. To compare the light curves in a consistent manner I parameterized them in terms of their time derivatives. My work is the first one implementing such analysis. We found distinct properties for the SNe II and IIb light curves. This leads to the conclusion that they most likely arise from different types of progenitors. For the second sample analysis, I used the novel technique of light curve time derivatives to study 54 rapid-cadence SNe Ia light curves from the CSP. Although the light curves of SNe Ia are homogeneous enough to be standardized and used as distance indicators, they present a subtle feature or “kink” soon after the i-band light curve peak that has been previously ignored. Analyzing the time derivatives, we were able to characterize the phase and strength of the kink. We could not directly link this feature to any other observed characteristic but we found that considering only the SNe with the strongest kinks substantially reduces the Hubble residuals. The third sample consists of the light curves and spectral series of six luminous SNe followed up by the Public European Southern Observatory Spectroscopic Survey of Transient Objects. The optical light curves of this sample are more luminous, exhibit bluer colors and decline faster than other SNe type II. The spectral series are blue at early times, they show weak or nonexistent metal lines, and broad and boxy Hα emission profiles with no associated absorption component. The shared characteristics support a similar powering scenario for all of them. We propose interaction with CSM that is not dense enough to be optically thick to electron scattering on large scales, which is consistent with the lack of narrow emission lines in the spectra. I will finish the talk by presenting the project I am currently working on, that involves the study of a large sample of SLSNe II. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-03-31 Mattia Sirressi (SU) 2023-04-07 No seminar (Långfredagen) 2023-04-14 Charlotte Mason (DAWN, NBI U. Copenhagen) The calendar for later planned seminars is available here . (Please note that calendar can be subject to updates) ——————————— Topic: Astronomy Department Seminar Time: March 24th, 2023 10:30 AM Stockholm Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 > On 17 Jan 2023, at 09:58, Eliot Ayache wrote: > > Dear all, > > The next SU astronomy departmental seminar will take place on Friday January 20th at 10:30 in room FC 61 (AlbaNova building, 6th floor) and on zoom. > > ——————————— > Speaker: Smaranika Banerjee > Title: Early kilonova from neutron star merger > https://www.albanova.se/event/early-kilonova-from-neutron-star-merger/ > > Abstract: > In binary neutron star (BNS) mergers, the radioactive decay of freshly synthesized heavy elements produces emissions in the ultraviolet-optical-infrared range, giving rise to a transient called a kilonova. The kilonova is an excellent probe to understand the origin of elements heavier than iron. The observational properties of the kilonova (light curve and spectra) depend on the bound-bound opacity of the heavy elements. Hence, a detailed opacity is necessary to model the realistic kilonova light curve and spectra. However, such calculations for opacity, and correspondingly, the realistic light curve, were largely unavailable, especially for the condition suitable at an early time (t < 1 day). > In my talk, I will discuss recent developments and challenges in modelling kilonova light curves. Also, I will share my recent work on opacity and light curve calculations of the kilonova, focusing on early time (t < 1 day). > ——————————— > > We look forward to seeing many of you there. Thanks! > > Eliot and Kris > > > > Upcoming Events: > > 2023-01-27 Mingjie Jian (SU) > 2023-02-03 Kelley Hess (IAA - Granada, Spain) > 2023-02-10 No seminar - OKC day > 2023-02-17 Diane Feuillet (Lund Obs.) > > > ——————————— > Topic: Astronomy Department Seminar Smaranika Banerjee > Time: Jan 20th, 2023 10:30 AM Stockholm > > Join Zoom Meeting: > https://stockholmuniversity.zoom.us/s/61002076352 > Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Tue Mar 21 10:58:57 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Tue, 21 Mar 2023 10:58:57 +0100 Subject: [Astronomy seminar] [CORRECTED] Astro Department Seminar - Fri March 24th 10:30 - Priscila Pessi In-Reply-To: <7FC5CE9E-553C-4483-AF6E-74CFC95CACE7@astro.su.se> References: <7FC5CE9E-553C-4483-AF6E-74CFC95CACE7@astro.su.se> Message-ID: Dear all, (Apologies for the double email.) The next SU astronomy departmental seminar will take place on Friday March 24th at 10:30 in room FC 61 (AlbaNova building, 6th floor) and on zoom. ——————————— Speaker: Priscila Pessi (SU) Title: Connecting observed properties of supernovae to progenitor scenarios https://www.albanova.se/event/astronomy-departmental-seminar-priscila-pessi-su/ Abstract: Supernovae (SNe) mark the explosive death of certain groups of stars. Theoretical models that take into account stellar evolution of predefined progenitor stars propose different explosion mechanisms. However, it is still not clear how the variation of characteristics such as metallicity, mass loss rate and multiplicity – among others – impact on the observed properties of SNe. Even when some models have been supported by observations, the scarcity of direct detections of progenitor stars prevents us from understanding the exact nature of the stars that explode as different types of SNe. In this talk I will present the observational analysis of three different SNe samples done during my PhD. The goal of the analysis is to associate observed characteristics to progenitor properties. The first studied sample consists of the light curves of 73 type II SNe from the Carnegie Supernova Project (CSP) and 21 type IIb SNe from the literature. To compare the light curves in a consistent manner I parameterized them in terms of their time derivatives. My work is the first one implementing such analysis. We found distinct properties for the SNe II and IIb light curves. This leads to the conclusion that they most likely arise from different types of progenitors. For the second sample analysis, I used the novel technique of light curve time derivatives to study 54 rapid-cadence SNe Ia light curves from the CSP. Although the light curves of SNe Ia are homogeneous enough to be standardized and used as distance indicators, they present a subtle feature or “kink” soon after the i-band light curve peak that has been previously ignored. Analyzing the time derivatives, we were able to characterize the phase and strength of the kink. We could not directly link this feature to any other observed characteristic but we found that considering only the SNe with the strongest kinks substantially reduces the Hubble residuals. The third sample consists of the light curves and spectral series of six luminous SNe followed up by the Public European Southern Observatory Spectroscopic Survey of Transient Objects. The optical light curves of this sample are more luminous, exhibit bluer colors and decline faster than other SNe type II. The spectral series are blue at early times, they show weak or nonexistent metal lines, and broad and boxy Hα emission profiles with no associated absorption component. The shared characteristics support a similar powering scenario for all of them. We propose interaction with CSM that is not dense enough to be optically thick to electron scattering on large scales, which is consistent with the lack of narrow emission lines in the spectra. I will finish the talk by presenting the project I am currently working on, that involves the study of a large sample of SLSNe II. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-03-31 Mattia Sirressi (SU) 2023-04-07 No seminar (Långfredagen) 2023-04-14 Charlotte Mason (DAWN, NBI U. Copenhagen) The calendar for later planned seminars is available here . (Please note that calendar can be subject to updates) ——————————— Topic: Astronomy Department Seminar Time: March 24th, 2023 10:30 AM Stockholm Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Mar 24 10:18:53 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 24 Mar 2023 10:18:53 +0100 Subject: [Astronomy seminar] [REMINDER] Astro Department Seminar - Fri March 24th 10:30 - Priscila Pessi In-Reply-To: <8467BD6D-055C-4E5F-9384-E0B116DB16A4@astro.su.se> References: <7FC5CE9E-553C-4483-AF6E-74CFC95CACE7@astro.su.se> <8467BD6D-055C-4E5F-9384-E0B116DB16A4@astro.su.se> Message-ID: Dear all, this is a friendly reminder about Priscilla’s seminar in 10 min! See you there! Kind regards, Eliot > On 21 Mar 2023, at 10:58, Eliot Ayache wrote: > > Dear all, > > (Apologies for the double email.) > > The next SU astronomy departmental seminar will take place on Friday March 24th at 10:30 in room FC 61 (AlbaNova building, 6th floor) and on zoom. > > ——————————— > Speaker: Priscila Pessi (SU) > Title: Connecting observed properties of supernovae to progenitor scenarios > https://www.albanova.se/event/astronomy-departmental-seminar-priscila-pessi-su/ > > Abstract: > Supernovae (SNe) mark the explosive death of certain groups of stars. Theoretical models that take into account stellar evolution of predefined progenitor stars propose different explosion mechanisms. However, it is still not clear how the variation of characteristics such as metallicity, mass loss rate and multiplicity – among others – impact on the observed properties of SNe. Even when some models have been supported by observations, the scarcity of direct detections of progenitor stars prevents us from understanding the exact nature of the stars that explode as different types of SNe. > > In this talk I will present the observational analysis of three different SNe samples done during my PhD. The goal of the analysis is to associate observed characteristics to progenitor properties. The first studied sample consists of the light curves of 73 type II SNe from the Carnegie Supernova Project (CSP) and 21 type IIb SNe from the literature. To compare the light curves in a consistent manner I parameterized them in terms of their time derivatives. My work is the first one implementing such analysis. We found distinct properties for the SNe II and IIb light curves. This leads to the conclusion that they most likely arise from different types of progenitors. > For the second sample analysis, I used the novel technique of light curve time derivatives to study 54 rapid-cadence SNe Ia light curves from the CSP. Although the light curves of SNe Ia are homogeneous enough to be standardized and used as distance indicators, they present a subtle feature or “kink” soon after the i-band light curve peak that has been previously ignored. Analyzing the time derivatives, we were able to characterize the phase and strength of the kink. We could not directly link this feature to any other observed characteristic but we found that considering only the SNe with the strongest kinks substantially reduces the Hubble residuals. > The third sample consists of the light curves and spectral series of six luminous SNe followed up by the Public European Southern Observatory Spectroscopic Survey of Transient Objects. The optical light curves of this sample are more luminous, exhibit bluer colors and decline faster than other SNe type II. The spectral series are blue at early times, they show weak or nonexistent metal lines, and broad and boxy Hα emission profiles with no associated absorption component. The shared characteristics support a similar powering scenario for all of them. We propose interaction with CSM that is not dense enough to be optically thick to electron scattering on large scales, which is consistent with the lack of narrow emission lines in the spectra. I will finish the talk by presenting the project I am currently working on, that involves the study of a large sample of SLSNe II. > > ——————————— > > We look forward to seeing many of you there. Thanks! > > Eliot and Kris > > > > Upcoming Events: > > 2023-03-31 Mattia Sirressi (SU) > 2023-04-07 No seminar (Långfredagen) > 2023-04-14 Charlotte Mason (DAWN, NBI U. Copenhagen) > > The calendar for later planned seminars is available here . > (Please note that calendar can be subject to updates) > > > > ——————————— > Topic: Astronomy Department Seminar > Time: March 24th, 2023 10:30 AM Stockholm > > Join Zoom Meeting: > https://stockholmuniversity.zoom.us/s/61002076352 > Meeting ID: 610 0207 6352 > -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Tue Mar 28 14:11:41 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Tue, 28 Mar 2023 14:11:41 +0200 Subject: [Astronomy seminar] Astro Department Seminar - Fri March 31st 10:30 - Mattia Sirressi In-Reply-To: <9B46CEDE-ACA8-48A1-B52C-A2ABD326BAAA@astro.su.se> References: <7FC5CE9E-553C-4483-AF6E-74CFC95CACE7@astro.su.se> <8467BD6D-055C-4E5F-9384-E0B116DB16A4@astro.su.se> <9B46CEDE-ACA8-48A1-B52C-A2ABD326BAAA@astro.su.se> Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday March 31st at 10:30 in room FC 61 (AlbaNova building, 6th floor) and on zoom. ——————————— Speaker: Mattia Sirressi (SU) Title: Star clusters as engines of galaxy evolution https://www.albanova.se/event/astronomy-departmental-seminar-mattia-sirressi-su/ Abstract: Feedback in star forming galaxies is the key process that regulates how many stars form given the available gas reservoir. For non-active galaxies the dominant source of feedback is represented by the ionising radiation, stellar winds and supernova explosions of massive stars. Young star clusters (YSCs) are the natural habitat of massive stars and inject large amounts of radiation, energy and momentum into the surrounding interstellar medium (ISM). After a brief introduction on star clusters, I will present a methodology that exploits the FUV spectroscopy of YSCs to study both the physical properties of the stellar population and the gas kinematics in the ISM. I will first show a study where the above method is employed for the starburst galaxy Haro 11. Secondly, I will present the results of the same type of analysis carried out for a sample of 20 YSCs named CLUES (CLusters in the Uv as EngineS). Thisstudy reveals for the first time the properties of outflows driven by YSCs at scales between tens and a few hundreds pc, which extend to smaller scales the relation found in previous works between galactic outflows and the star-formation properties of host galaxies. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-04-07 No seminar (Långfredagen) 2023-04-14 Charlotte Mason (DAWN, NBI U. Copenhagen) 2023-04-21 Tadafumi Matsuno (Kapteyn Institute, U. Groningen) The calendar for later planned seminars is available here . (Please note that calendar can be subject to updates) ——————————— Topic: Astronomy Department Seminar Time: March 31st, 2023 10:30 AM Stockholm Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Mar 31 10:17:30 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 31 Mar 2023 10:17:30 +0200 Subject: [Astronomy seminar] Astro Department Seminar - Fri March 31st 10:30 - Mattia Sirressi In-Reply-To: <16ED9E09-811D-40A7-928C-87E026404717@astro.su.se> References: <7FC5CE9E-553C-4483-AF6E-74CFC95CACE7@astro.su.se> <8467BD6D-055C-4E5F-9384-E0B116DB16A4@astro.su.se> <9B46CEDE-ACA8-48A1-B52C-A2ABD326BAAA@astro.su.se> <16ED9E09-811D-40A7-928C-87E026404717@astro.su.se> Message-ID: Hi everyone, This is a reminder about Mattia’s seminar in 15min in FC61 and on zoom. https://stockholmuniversity.zoom.us/s/61002076352 See you all there! Kind regards, Eliot > On 28 Mar 2023, at 14:11, Eliot Ayache wrote: > > Dear all, > > The next SU astronomy departmental seminar will take place on Friday March 31st at 10:30 in room FC 61 (AlbaNova building, 6th floor) and on zoom. > > ——————————— > Speaker: Mattia Sirressi (SU) > Title: Star clusters as engines of galaxy evolution > https://www.albanova.se/event/astronomy-departmental-seminar-mattia-sirressi-su/ > > Abstract: > Feedback in star forming galaxies is the key process that regulates how many stars form given the available gas reservoir. For non-active galaxies the dominant source of feedback is represented by the ionising radiation, stellar winds and supernova explosions of massive stars. Young star clusters (YSCs) are the natural habitat of massive stars and inject large amounts of radiation, energy and momentum into the surrounding interstellar medium (ISM). > After a brief introduction on star clusters, I will present a methodology that exploits the FUV spectroscopy of YSCs to study both the physical properties of the stellar population and the gas kinematics in the ISM. I will first show a study where the above method is employed for the starburst galaxy Haro 11. Secondly, I will present the results of the same type of analysis carried out for a sample of 20 YSCs named CLUES (CLusters in the Uv as EngineS). Thisstudy reveals for the first time the properties of outflows driven by YSCs at scales between tens and a few hundreds pc, which extend to smaller scales the relation found in previous works between galactic outflows and the star-formation properties of host galaxies. > > ——————————— > > We look forward to seeing many of you there. Thanks! > > Eliot and Kris > > > > Upcoming Events: > > 2023-04-07 No seminar (Långfredagen) > 2023-04-14 Charlotte Mason (DAWN, NBI U. Copenhagen) > 2023-04-21 Tadafumi Matsuno (Kapteyn Institute, U. Groningen) > > The calendar for later planned seminars is available here . > (Please note that calendar can be subject to updates) > > > > ——————————— > Topic: Astronomy Department Seminar > Time: March 31st, 2023 10:30 AM Stockholm > > Join Zoom Meeting: > https://stockholmuniversity.zoom.us/s/61002076352 > Meeting ID: 610 0207 6352 > -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Tue Apr 11 16:42:56 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Tue, 11 Apr 2023 16:42:56 +0200 Subject: [Astronomy seminar] Astro Department Seminar - Fri Apr 14th 10:30 - Charlotte Mason (DAWN) In-Reply-To: References: Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday April 14th at 10:30 in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352 ). ——————————— Speaker: Charlotte Mason (DAWN, NBI U. Copenhagen) Title: Chasing Cosmic Dawn and Reionization https://www.albanova.se/event/astronomy-departmental-seminar-charlotte-mason-dawn/ Abstract: The newly launched James Webb Space Telescope (JWST) has expanded our cosmic horizon to the first few hundred million years after the Big Bang, enabling us to observe the build up of the first galaxies. These first galaxies fundamentally altered their surroundings by 're'-ionizing intergalactic hydrogen. I will describe how this reionization process is still poorly understood, but how identifying when reionization began and which population of galaxies dominated the process is key to constraining poorly understood astrophysics of galaxy formation (e.g. massive star formation and feedback processes). Excitingly, an excess of luminous galaxy candidates just 500 million years after the Big Bang has been discovered in early JWST data, which exceeds theoretical predictions. I will discuss how the new JWST observations test theoretical models and possible solutions. I will present efforts to constrain the timeline of reionization, which favour a late and rapid end to reionization. I will discuss how JWST observations of Lyman alpha emission at z>8 challenge these results and discuss the implications for our understanding of early star formation. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-04-21 Tadafumi Matsuno (Kapteyn Institute, U. Groningen) 2023-04-26 Alexandra Lereste (SU) <— Note this is on a Wednesday (time TBD) 2023-04-28 Biwei Jiang (Beijing Normal University) The calendar for later planned seminars is available here . (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 > -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Apr 17 15:45:55 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 17 Apr 2023 13:45:55 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday April 21st - Tadafumi Matsuno (University of Groningen) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday April 21st at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ——————————— Speaker: Tadafumi Matsuno (Kapteyn Institute, U. Groningen) Title: Chemical evolution of disrupted dwarf galaxies in the Milky Way https://www.albanova.se/event/astronomy-departmental-seminar-tadafumi-matsuno-groningen/ Abstract: Thanks to the Gaia mission, we can now identify promising candidates for dwarf galaxies that have been accreted and disrupted by the Milky Way as substructures in stellar kinematics. In this talk, I will briefly summarize a method to identify these kinematic substructures and discuss our efforts to characterize the detailed chemical abundances of stars selected as their members. We reveal distinct differences in abundance ratios among kinematic substructures, which can be attributed to varying contributions by type Ia supernovae in their chemical enrichments. Additionally, I will show that the chemical abundance ratios of these kinematic substructures offer a unique opportunity to test our understanding of nucleosynthesis of elements. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris Upcoming Events: 2023-04-26 Alexandra Lereste (SU) <— Note this is on a Wednesday (time TBD) 2023-04-28 Biwei Jiang (Beijing Normal University) 2023-05-05 Natalia Lahen (MPA Garching) The calendar for later planned seminars is available here. (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Wed Apr 19 16:26:36 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Wed, 19 Apr 2023 16:26:36 +0200 Subject: [Astronomy seminar] [Extra session] Astro Department Seminar - Wed Apr 26th 14:30 - Alexandra Lereste (SU) In-Reply-To: <80CA244A-FA9B-424B-A0D1-D66C1D97285D@astro.su.se> References: <80CA244A-FA9B-424B-A0D1-D66C1D97285D@astro.su.se> Message-ID: Dear all, (Note the unusual time) Exceptionally, we will have a session of the SU astronomy departmental seminar on Wednesday April 26th at 14:30 in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352 ). There are still scheduled seminars on Friday 21st and Friday 28th. ——————————— Speaker: Alexandra Lereste (SU) Title: Neutral gas properties of high-redshift analog galaxies: 21cm observations of Lyα and LyC-emitting galaxies https://www.albanova.se/event/astronomy-departmental-seminar-alexandra-lereste-su/ Abstract: Neutral hydrogen (HI) is the most abundant baryonic element and a crucial component of galaxies. In the early universe, the interaction between neutral gas and the UV light produced by galaxies is thought to have given rise to the last major phase transition of the Universe: cosmological reionization. During reionization the bulk of HI within the intergalactic medium (IGM) was ionized. However, observational constraints limit our understanding of the interplay between the radiation produced by galaxies and their neutral gas, and that of the physical processes that caused this important cosmological period. Another poorly understood mechanism is the one that drives the escape of Lyman-α (Lyα) emission from star-forming galaxies and shapes the line profile of this well-used tracer of galaxies at high redshift. To fully solve these problems, direct observations of the neutral gas content and distribution of Lyα and ionizing radiation emitters are needed. In this talk, I will present 21cm observations of the neutral gas reservoirs of rare local galaxies that are analogous to objects in the early universe. We have observed the neutral gas of Haro 11, the closest known ionizing radiation (Lyman Continuum, LyC) leaking galaxy. This 21cm observation was the first to successfully map the neutral gas distribution of a confirmed LyC emitter. We observed a strongly asymmetric neutral gas distribution resulting from a merger event, with the bulk of the HI mass offset from the regions producing LyC radiation in the galaxy. By decreasing the column density of gas on large scales, this HI distribution has facilitated the escape of ionizing radiation from the center of the galaxy to the IGM. We have also observed the neutral gas content and distribution of local Lyα-emitting galaxies on a variety of angular scales. We found that global HI properties did not correlate well with any metric quantifying Lyα emission, but resolved 21cm observations show tentative trends between Lyα and HI properties. This indicates that if neutral gas regulates the escape of Lyα emission, it does so on small scales. Furthermore, we have found clear evidence of interaction in most of the galaxies in the sample (>60%), indicating that mergers also play an important role in the Lyα escape from galaxies. According to cosmological models, galaxy mergers occurred more frequently in the early universe. Assessing the contribution of environment and galaxy interactions at high redshift will be essential to fully understand the first billion years of our universe. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris The calendar for later planned seminars is available here . (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Apr 24 15:31:06 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 24 Apr 2023 13:31:06 +0000 Subject: [Astronomy seminar] SU astronomy departmental seminar Friday April 28th - Biwei Jiang (Beijing Normal University) Message-ID: Dear all, It is our pleasure to announce that this week we will have Biwei Jiang visiting us here at Stockholm University, all the way from Beijing Normal University, and giving this Friday's SU astronomy departmental seminar on April 28th at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ——————————— Speaker: Biwei Jiang (Beijing Normal University, BNU) Title: The sample and mass loss rate of red supergiants in M31 and M33 https://www.albanova.se/event/7310/ Abstract: Red supergiants (RSGs) are important contributors to interstellar medium through massive winds. Due to serious interstellar extinction, the complete sample of RSGs is extremely difficult to obtain in our Galaxy. As two of the largest spiral galaxies in the Local Group, M31 and M33 can serve as references to analyze the global contribution of RSGs to the galactic medium. By using evident branching of red dwarfs and red (super)giants in the near-infrared color-color (J-H/H-K) diagram, the foreground dwarf stars are excluded efficiently with the UKIRT observational data, The most complete and pure sample of RSGs in M31 and M33, specifically, 5498 and 3055 RSGs respectively, are obtained from the color-magnitude ( J-K/K) diagram of the member stars. The dust radiative transfer model, the DUSTY code, is run to calculate the mass loss rate of RSGs. The average mass loss rate of RSGs is found to be around 2.0 × 10-5 M☉ yr-1 with a gas-to-dust ratio of 100, which yields a total contribution to the interstellar dust of about 1.1 × 10-3 M☉ yr-1 in M31 and 6.0 × 10-4 M☉ yr-1 in M33, a non-negligible source in comparison with evolved low-mass stars. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris --- Note, there will also be an additional seminar this week on Wednesday April 26th at 14:30 in room FC61 by our own Alexandra Lereste (SU). --- Upcoming Events: 2023-04-26 Alexandra Lereste (SU) <— Note this is on a Wednesday (time 14:30 - followed by Fika) 2023-05-05 Natalia Lahen (MPA Garching) 2023-05-12 Jin Koda (Stony Brooke University) The calendar for later planned seminars is available here. (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Wed Apr 26 14:08:21 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Wed, 26 Apr 2023 14:08:21 +0200 Subject: [Astronomy seminar] [Extra session] Astro Department Seminar - Wed Apr 26th 14:30 - Alexandra Le Reste (SU) In-Reply-To: <03279651-8085-4A7D-A80A-08D56E9E3438@astro.su.se> References: <80CA244A-FA9B-424B-A0D1-D66C1D97285D@astro.su.se> <03279651-8085-4A7D-A80A-08D56E9E3438@astro.su.se> Message-ID: Dear all, This is a friendly reminder for Alexandra’s seminar in 20min in FC61 and on Zoom. https://stockholmuniversity.zoom.us/s/61002076352 We hope to see many of you there! Kind regards, Eliot Ayache > On 19 Apr 2023, at 16:26, Eliot Ayache wrote: > > Dear all, > > (Note the unusual time) > > Exceptionally, we will have a session of the SU astronomy departmental seminar on Wednesday April 26th at 14:30 in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352 ). > > There are still scheduled seminars on Friday 21st and Friday 28th. > > ——————————— > Speaker: Alexandra Le Reste (SU) > Title: Neutral gas properties of high-redshift analog galaxies: 21cm observations of Lyα and LyC-emitting galaxies > https://www.albanova.se/event/astronomy-departmental-seminar-alexandra-lereste-su/ > > Abstract: > Neutral hydrogen (HI) is the most abundant baryonic element and a crucial component of galaxies. In the early universe, the interaction between neutral gas and the UV light produced by galaxies is thought to have given rise to the last major phase transition of the Universe: cosmological reionization. During reionization the bulk of HI within the intergalactic medium (IGM) was ionized. However, observational constraints limit our understanding of the interplay between the radiation produced by galaxies and their neutral gas, and that of the physical processes that caused this important cosmological period. Another poorly understood mechanism is the one that drives the escape of Lyman-α (Lyα) emission from star-forming galaxies and shapes the line profile of this well-used tracer of galaxies at high redshift. To fully solve these problems, direct observations of > the neutral gas content and distribution of Lyα and ionizing radiation emitters are needed. > In this talk, I will present 21cm observations of the neutral gas reservoirs of rare local galaxies that are analogous to objects in the early universe. We have observed the neutral gas of Haro 11, the closest known ionizing radiation (Lyman Continuum, LyC) leaking galaxy. This 21cm observation was the first to successfully map the neutral gas distribution of a confirmed LyC emitter. We observed a strongly asymmetric neutral gas distribution resulting from a merger event, with the bulk of the HI mass offset from the regions producing LyC radiation in the galaxy. By decreasing the column density of gas on large scales, this HI distribution has facilitated the escape of ionizing radiation from the center of the galaxy to the IGM. > We have also observed the neutral gas content and distribution of local Lyα-emitting galaxies on a variety of angular scales. We found that global HI properties did not correlate well with any metric quantifying Lyα emission, but resolved 21cm observations show tentative trends between Lyα and HI properties. This indicates that if neutral gas regulates the escape of Lyα emission, it does so on small scales. Furthermore, we have found clear evidence of interaction in most of the galaxies in the sample (>60%), indicating that mergers also play an important role in the Lyα escape from galaxies. According to cosmological models, galaxy mergers occurred more frequently in the early universe. Assessing the contribution of environment and galaxy interactions at high redshift will be essential to fully understand the first billion years of our universe. > ——————————— > > > We look forward to seeing many of you there. Thanks! > > Eliot and Kris > > The calendar for later planned seminars is available here . > (Please note that calendar can be subject to updates) > > ——————————— > Join Zoom Meeting: > https://stockholmuniversity.zoom.us/s/61002076352 > Meeting ID: 610 0207 6352 > > -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Tue May 2 10:43:40 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Tue, 2 May 2023 10:43:40 +0200 Subject: [Astronomy seminar] =?utf-8?q?Astro_Department_Seminar_-_Fri_May_?= =?utf-8?q?5th_10=3A30_-_Natalia_Lah=C3=A9n_=28MPIA=29?= In-Reply-To: <2DE80C8F-1A02-4955-AAA1-58C2F474DF11@astro.su.se> References: <80CA244A-FA9B-424B-A0D1-D66C1D97285D@astro.su.se> <03279651-8085-4A7D-A80A-08D56E9E3438@astro.su.se> <2DE80C8F-1A02-4955-AAA1-58C2F474DF11@astro.su.se> Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday May 5th at 10:30 in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352 ). ——————————— Speaker: Natalia Lahén (MPIA) Title: The formation of star clusters in low-metallicity environments https://www.albanova.se/event/astronomy-departmental-seminar-natalia-lahen-mpia/ Abstract: Despite the efforts of observational surveys to map the formation sites of globular clusters (GCs) at redshifts beyond z~2, the spatial resolution even in the deepest lensing surveys will still be limited to scales of parsecs. Numerical experiments with star forming environments typical to high-redshift Universe are therefore needed to probe the formation of GCs down to the details of their internal structure. In the GRIFFIN project, we model the formation of stars, star clusters and GCs in low-metallicity gas-rich dwarf galaxies. We use the SPHGal code, modified from GADGET-3, that includes a chemical network to model the low-temperature cooling of the multiphase ISM. Star formation and feedback prescriptions include a fully realized IMF and feedback from single stars. Using isolated and merging dwarf galaxy models, we are able to follow the formation and evolution of star clusters within their full galactic environments. I will discuss how massive star clusters up to the mass range of GCs form in the most extreme star-forming environments probed by our simulations. In our new simulations, we implement the element-by-element enrichment of the ISM by stellar winds and supernovae of massive stars, and investigate the build-up of chemical variations within the stellar populations of massive star clusters. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris The calendar for later planned seminars is available here . (Please note that calendar can be subject to updates) Upcoming weeks: 2023-05-12 Jin Koda (Stony Brook University) 2023-05-19 no seminar (klämdag) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri May 5 10:19:24 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 5 May 2023 10:19:24 +0200 Subject: [Astronomy seminar] =?utf-8?q?Astro_Department_Seminar_-_Fri_May?= =?utf-8?q?_5th_10=3A30_-_Natalia_Lah=C3=A9n_=28MPIA=29?= In-Reply-To: <99CBC330-6A55-4F6E-AD24-520FF483BCA5@astro.su.se> References: <80CA244A-FA9B-424B-A0D1-D66C1D97285D@astro.su.se> <03279651-8085-4A7D-A80A-08D56E9E3438@astro.su.se> <2DE80C8F-1A02-4955-AAA1-58C2F474DF11@astro.su.se> <99CBC330-6A55-4F6E-AD24-520FF483BCA5@astro.su.se> Message-ID: Dear all, This is a friendly reminder about Natalia’s seminar happening in 10 minutes in FC61 and on zoom! We hope to see many of you there. Kind regards, Eliot > On 2 May 2023, at 10:43, Eliot Ayache wrote: > > Dear all, > > The next SU astronomy departmental seminar will take place on Friday May 5th at 10:30 in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352 ). > > > ——————————— > Speaker: Natalia Lahén (MPIA) > Title: The formation of star clusters in low-metallicity environments > https://www.albanova.se/event/astronomy-departmental-seminar-natalia-lahen-mpia/ > > Abstract: > Despite the efforts of observational surveys to map the formation sites > of globular clusters (GCs) at redshifts beyond z~2, the spatial > resolution even in the deepest lensing surveys will still be limited to > scales of parsecs. Numerical experiments with star forming environments > typical to high-redshift Universe are therefore needed to probe the > formation of GCs down to the details of their internal structure. In the > GRIFFIN project, we model the formation of stars, star clusters and GCs > in low-metallicity gas-rich dwarf galaxies. We use the SPHGal code, > modified from GADGET-3, that includes a chemical network to model the > low-temperature cooling of the multiphase ISM. Star formation and > feedback prescriptions include a fully realized IMF and feedback from > single stars. Using isolated and merging dwarf galaxy models, we are > able to follow the formation and evolution of star clusters within their > full galactic environments. I will discuss how massive star clusters up > to the mass range of GCs form in the most extreme star-forming > environments probed by our simulations. In our new simulations, we > implement the element-by-element enrichment of the ISM by stellar winds > and supernovae of massive stars, and investigate the build-up of > chemical variations within the stellar populations of massive star > clusters. > ——————————— > > > We look forward to seeing many of you there. Thanks! > > Eliot and Kris > > > The calendar for later planned seminars is available here . > (Please note that calendar can be subject to updates) > > Upcoming weeks: > 2023-05-12 Jin Koda (Stony Brook University) > 2023-05-19 no seminar (klämdag) > > > ——————————— > Join Zoom Meeting: > https://stockholmuniversity.zoom.us/s/61002076352 > Meeting ID: 610 0207 6352 > > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Tue May 9 08:42:40 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Tue, 9 May 2023 08:42:40 +0200 Subject: [Astronomy seminar] Astro Department Seminar - Fri May 12th 10:30 - Jin Koda (Stony Brook U. & Paris Observatory) In-Reply-To: References: <80CA244A-FA9B-424B-A0D1-D66C1D97285D@astro.su.se> <03279651-8085-4A7D-A80A-08D56E9E3438@astro.su.se> <2DE80C8F-1A02-4955-AAA1-58C2F474DF11@astro.su.se> <99CBC330-6A55-4F6E-AD24-520FF483BCA5@astro.su.se> Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday May 12th at 10:30 in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352 ). https://www.albanova.se/event/astronomy-departmental-seminar-jin-koda-psl/ ——————————— Speaker: Jin Koda (Stony Brook University, USA - on sabbatical leave - & Paris Observatory - visiting -) Title: Molecular cloud evolution as the first step for star formation and galaxy evolution Abstract: Molecular gas and clouds host virtually all star formation, and therefore, their formation and evolution are the first step leading to star formation and galaxy evolution. On the basis of broad observational data, I will discuss how molecular gas and clouds evolve in the Milky Way and nearby spiral galaxies. In particular, I will argue for a long cloud lifetime (>~100 Myr), as opposed to the recently-suggested short lifetime (<~10-30 Myr). Simply put, we see molecular gas but don't see much atomic gas within galactic disks, even in the inter-arm regions, and thus the gas stays molecular. In this picture, star formation does not occur at the onset of gravitational collapse from atomic gas to molecular clouds, but is triggered in the long-existing molecular clouds. This view contradicts the traditional picture of the spiral density-wave theory, which predicts a rapid gas phase transition -- from atomic to molecular and then to atomic -- through spiral arm passage. Instead, the gas evolves through the coagulation and fragmentation of molecular clouds. The consequences of this revised view of cloud evolution, star formation, and galaxy evolution will be outlined. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris The calendar for later planned seminars is available here . (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri May 12 10:22:05 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 12 May 2023 10:22:05 +0200 Subject: [Astronomy seminar] Astro Department Seminar - Fri May 12th 10:30 - Jin Koda (Stony Brook U. & Paris Observatory) In-Reply-To: References: <80CA244A-FA9B-424B-A0D1-D66C1D97285D@astro.su.se> <03279651-8085-4A7D-A80A-08D56E9E3438@astro.su.se> <2DE80C8F-1A02-4955-AAA1-58C2F474DF11@astro.su.se> <99CBC330-6A55-4F6E-AD24-520FF483BCA5@astro.su.se> Message-ID: Hi everyone, This is a reminder about Jin Koda’s seminar in 10 minutes! See you there! Kind regards, Eliot > On 9 May 2023, at 08:42, Eliot Ayache wrote: > > Dear all, > > The next SU astronomy departmental seminar will take place on Friday May 12th at 10:30 in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352 ). > https://www.albanova.se/event/astronomy-departmental-seminar-jin-koda-psl/ > > > ——————————— > Speaker: Jin Koda (Stony Brook University, USA - on sabbatical leave - & Paris Observatory - visiting -) > Title: Molecular cloud evolution as the first step for star formation and galaxy evolution > > > Abstract: > Molecular gas and clouds host virtually all star formation, and therefore, their formation and evolution are the first step leading to star formation and galaxy evolution. On the basis of broad observational data, I will discuss how molecular gas and clouds evolve in the Milky Way and nearby spiral galaxies. In particular, I will argue for a long cloud lifetime (>~100 Myr), as opposed to the recently-suggested short lifetime (<~10-30 Myr). Simply put, we see molecular gas but don't see much atomic gas within galactic disks, even in the inter-arm regions, and thus the gas stays molecular. In this picture, star formation does not occur at the onset of gravitational collapse from atomic gas to molecular clouds, but is triggered in the long-existing molecular clouds. This view contradicts the traditional picture of the spiral density-wave theory, which predicts a rapid gas phase transition -- from atomic to molecular and then to atomic -- through spiral arm passage. Instead, the gas evolves through the coagulation and fragmentation of molecular clouds. The consequences of this revised view of cloud evolution, star formation, and galaxy evolution will be outlined. > ——————————— > > > We look forward to seeing many of you there. Thanks! > > Eliot and Kris > > > The calendar for later planned seminars is available here . > (Please note that calendar can be subject to updates) > > > ——————————— > Join Zoom Meeting: > https://stockholmuniversity.zoom.us/s/61002076352 > Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Tue May 30 13:19:23 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Tue, 30 May 2023 11:19:23 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday June 2nd - Bibiana Prinoth (Lund University) Message-ID: Dear all, It is my pleasure to announce the next SU astronomy departmental seminar that will take place on Friday June 2nd at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ——————————— Speaker: Bibiana Prinoth (Lund University) Title: Exploring the atmosphere of the ultra-hot Jupiter WASP-189 b https://www.albanova.se/event/astronomy-departmental-seminar-bibiana-prinoth-lund/ Abstract: With the discovery of the first exoplanet orbiting a Sun-like star, a class of highly irradiated planets has emerged that has fundamentally changed our view of planetary systems. These planets are different from the planets in our own solar system and therefore offer a unique perspective on the atmospheric chemistry and thermal structure of the hottest extrasolar gas giants. One of these gas giants is the ultra-hot Jupiter WASP-189 b, a planet very close to its host star and subject to extreme conditions. Although it has not been studied as intensively as its slightly colder siblings, the dynamical effects and richness of the transmission spectrum of this planet have caught our attention and raise the question: What else is there to see? In this talk, we will study the atmosphere of this planet as seen in the transmission spectrum using high-resolution spectrographs from around the world. After the first study published last year, in which we discovered nine different species, including titanium oxide, we have followed up with two more spectrographs to paint a more coherent picture that allows us to detected and investigate asymmetries in the signals. In this talk, I will take you from the observations to the discoveries and their implications for chemistry, temperature and dynamics, and try to close the circle by placing the planet in the larger context of ultra-hot Jupiters. ——————————— We look forward to seeing many of you there. Thanks! Eliot and Kris *Note, this will be the finals seminar before the summer break. Seminars will resume again in September. Upcoming Events: 2023-06-09 PhD Defence Mattia Sirressi - no seminar Summer break until September The calendar for later planned seminars is available here. (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Jun 9 09:23:25 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 9 Jun 2023 07:23:25 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Tuesday June 13th at 10:00am - Raymond Pierrehumbert (University of Oxford) Message-ID: Dear all, In light of a special visitor at the department next week, we have decided to have one last SU astronomy departmental seminar before the summer break. It will take place on Tuesday, June 13th at 10:00am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). The speaker will be Raymond T. Pierrehumbert from the University of Oxford. He will also be visiting the Meteorology department at SU next week as well as the Astronomy department, so please reach out to him directly if you would like to arrange a meeting. Please note the unusual day and time, **Tuesday, June13th at 10:00am**. A reminder email will be sent out on Tuesday morning. ——————————— Speaker: Raymond T. Pierrehumbert (University of Oxford) Title: Subneptune atmospheres linked to interior structure https://www.albanova.se/event/astronomy-departmental-seminar-raymond-t-pierrehumbert-university-of-oxford/ Abstract: I will introduce the subNeptune class of planets, which are estimated to be the most common kind of planets in the Universe (if one can extrapolate from our local region of the Milky Way Galaxy); Possible vertical structures and compositions are discussed, with particular emphasis on the way compositional inhibition of convection from silicate vapor in water or H2, or water vapor in H2 can affect the thermal structure and mass-radius relation. The importance of coupling interior structure models to self-consistent atmospheres is emphasised, and in particular the implications of the runaway greenhouse threshold for the interior state of subNeptunes are discussed. Some highlights of current and planed JWST observations of subNeptunes are discussed. ——————————— We look forward to seeing many of you there. Thanks! Kris and Eliot *Note, this will be the final seminar before the summer break. Seminars will resume again in September. The calendar for later planned seminars is available here. (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Jun 12 21:44:11 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 12 Jun 2023 19:44:11 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Tuesday June 13th at 10:00am - Raymond Pierrehumbert (University of Oxford) In-Reply-To: References: Message-ID: Dear all, This is a reminder of the SU astronomy departmental seminar that will take place tomorrow, Tuesday, June 13th at 10:00am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). The speaker will be Raymond T. Pierrehumbert from the University of Oxford. He will also be visiting the Meteorology department at SU this week as well as the Astronomy department, so please reach out to him directly if you would like to arrange a meeting. Please note the unusual day and time, **Tuesday, June13th at 10:00am**. ——————————— Speaker: Raymond T. Pierrehumbert (University of Oxford) Title: Subneptune atmospheres linked to interior structure https://www.albanova.se/event/astronomy-departmental-seminar-raymond-t-pierrehumbert-university-of-oxford/ Abstract: I will introduce the subNeptune class of planets, which are estimated to be the most common kind of planets in the Universe (if one can extrapolate from our local region of the Milky Way Galaxy); Possible vertical structures and compositions are discussed, with particular emphasis on the way compositional inhibition of convection from silicate vapor in water or H2, or water vapor in H2 can affect the thermal structure and mass-radius relation. The importance of coupling interior structure models to self-consistent atmospheres is emphasised, and in particular the implications of the runaway greenhouse threshold for the interior state of subNeptunes are discussed. Some highlights of current and planed JWST observations of subNeptunes are discussed. ——————————— We look forward to seeing many of you there. Thanks! Kris and Eliot *Note, this will be the final seminar before the summer break. Seminars will resume again in September. The calendar for later planned seminars is available at https://ttt.astro.su.se/ical/astro-seminars.ics. (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 ________________________________ From: Kristopher Charles Youakim Sent: Friday, June 9, 2023 9:23:25 AM To: alla at astro.su.se Cc: raymond.pierrehumbert at physics.ox.ac.uk Subject: Astronomy departmental seminar Tuesday June 13th at 10:00am - Raymond Pierrehumbert (University of Oxford) Dear all, In light of a special visitor at the department next week, we have decided to have one last SU astronomy departmental seminar before the summer break. It will take place on Tuesday, June 13th at 10:00am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). The speaker will be Raymond T. Pierrehumbert from the University of Oxford. He will also be visiting the Meteorology department at SU next week as well as the Astronomy department, so please reach out to him directly if you would like to arrange a meeting. Please note the unusual day and time, **Tuesday, June13th at 10:00am**. A reminder email will be sent out on Tuesday morning. ——————————— Speaker: Raymond T. Pierrehumbert (University of Oxford) Title: Subneptune atmospheres linked to interior structure https://www.albanova.se/event/astronomy-departmental-seminar-raymond-t-pierrehumbert-university-of-oxford/ Abstract: I will introduce the subNeptune class of planets, which are estimated to be the most common kind of planets in the Universe (if one can extrapolate from our local region of the Milky Way Galaxy); Possible vertical structures and compositions are discussed, with particular emphasis on the way compositional inhibition of convection from silicate vapor in water or H2, or water vapor in H2 can affect the thermal structure and mass-radius relation. The importance of coupling interior structure models to self-consistent atmospheres is emphasised, and in particular the implications of the runaway greenhouse threshold for the interior state of subNeptunes are discussed. Some highlights of current and planed JWST observations of subNeptunes are discussed. ——————————— We look forward to seeing many of you there. Thanks! Kris and Eliot *Note, this will be the final seminar before the summer break. Seminars will resume again in September. The calendar for later planned seminars is available here. (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Aug 28 13:48:24 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 28 Aug 2023 13:48:24 +0200 Subject: [Astronomy seminar] Astronomy departmental seminar Friday September 1st at 10:30am - Janez Kos (University of Ljubljana) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday September 1st at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ——————————— Speaker: Janez Kos (University of Ljubljana) Title: Tidal tails of open clusters https://www.albanova.se/event/janez-kos/ Abstract: Tidal tails of open clusters have first been observed only in the recent couple of years. Like the tails of globular clusters and satellite galaxies, they can be used as important probes of gravitational fields, galactic evolution, disk kinematics, and stellar evolution. Recent progress has been possible with the arrival of Gaia data releases, so we can find tails of structures 1000 times smaller than globular clusters in the environment 1000 times denser than the halo. I will present a probabilistic method that does not directly rely on finding overdensities. We use simulations of cluster disintegration to define likelihoods for Gaia stars to be cluster members, and simulations of the Galactic stellar population to define membership probabilities. In an analysis of 500 clusters, we reliably find stars in tidal tails 1000 pc away from cluster cores. I will also discuss the need for precise radial velocities (not used in our method), obtaining more complete mass functions, and observed oddities that hint at numerous kinematical processes that shape the tidal tails. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-09-08 Mattia Bulla (University of Ferrara) 2023-09-15 TBD 2023-09-22 Henk Spruit (MPIA) You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Sep 1 09:44:34 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 1 Sep 2023 09:44:34 +0200 Subject: [Astronomy seminar] Reminder: Astronomy departmental seminar Friday September 1st at 10:30am - Janez Kos (University of Ljubljana) Message-ID: Dear all, This is a reminder of the weekly SU astronomy departmental seminar that will take place in about 45 minutes, *at 10:30am in room FC61* (AlbaNova building, 6th floor) *and on zoom* (https://stockholmuniversity.zoom.us/s/61002076352). This is the first seminar after the summer break and as usual, we encourage you to attend in person if possible. ________________________________________________ ***Speaker: Janez Kos (Ljubljana University) * *Title: Tidal tails of open clusters* https://www.albanova.se/event/janez-kos/ Abstract: Tidal tails of open clusters have first been observed only in the recent couple of years. Like the tails of globular clusters and satellite galaxies, they can be used as important probes of gravitational fields, galactic evolution, disk kinematics, and stellar evolution. Recent progress has been possible with the arrival of Gaia data releases, so we can find tails of structures 1000 times smaller than globular clusters in the environment 1000 times denser than the halo. I will present a probabilistic method that does not directly rely on finding overdensities. We use simulations of cluster disintegration to define likelihoods for Gaia stars to be cluster members, and simulations of the Galactic stellar population to define membership probabilities. In an analysis of 500 clusters, we reliably find stars in tidal tails 1000 pc away from cluster cores. I will also discuss the need for precise radial velocities (not used in our method), obtaining more complete mass functions, and observed oddities that hint at numerous kinematical processes that shape the tidal tails. ________________________________________________ We look forward to seeing many of you there. Thanks! Adur and Adélaïde You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) Upcoming Events: 2023-09-08 Mattia Bulla (University of Ferrara) 2023-09-15 SU-UU conference (no astronomy seminar) 2023-09-22 Henk Spruit (MPIA) ________________________________________________ Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Sep 18 16:49:05 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 18 Sep 2023 14:49:05 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday September 22nd at 10:30am - Hendrik C. Spruit (Max Planck Institute for Astrophysics) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday September 22nd at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ——————————— Speaker: Prof. Hendrik C. Spruit (Max Planck Institute for Astrophysics) Title: Historical overview (and misconceptions) of convection in solar/stellar atmospheres Event: https://indico.fysik.su.se/e/hendrik-spruit Abstract: Controversial discussions about the nature of the Sun's granulation date back almost a century. How can a flow with a Reynolds number of 10^12 look more like a bowl of soup than ferocious turbulence? After a historical overview I discuss how the answer is closely related to a misconception about the forces that drive the granulation as they are observed in ever improving observations and realistic numerical simulations. A closer look at this problem also explains the so-called 'convection conundrum': the discrepancy between results from helioseismic measurements of subsurface flows' on the one hand and 'whole convection zone' simulations on the other. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-09-28 Nestor Espinoza (**DIFFERENT DATE AND PLACE!!**) 2023-10-06 Matilde Mingozzi 2023-10-13 Guillaume Guiglion You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Sep 22 09:46:32 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 22 Sep 2023 09:46:32 +0200 Subject: [Astronomy seminar] Reminder: Astronomy departmental seminar Friday September 22nd at 10:30am - Hendrik C. Spruit (Max Planck Institute for Astrophysics) Message-ID: Dear all, This is a reminder of the weekly SU astronomy departmental seminar that will take place in about 45 minutes, *at 10:30am in room FC61* (AlbaNova building, 6th floor) *and on zoom* (https://stockholmuniversity.zoom.us/s/61002076352). As usual, we encourage you to attend in person if possible. ——————————— Speaker: Prof. Hendrik C. Spruit (Max Planck Institute for Astrophysics) Title: Historical overview (and misconceptions) of convection in solar/stellar atmospheres Event: https://indico.fysik.su.se/e/hendrik-spruit Abstract: Controversial discussions about the nature of the Sun's granulation date back almost a century. How can a flow with a Reynolds number of 10^12 look more like a bowl of soup than ferocious turbulence? After a historical overview I discuss how the answer is closely related to a misconception about the forces that drive the granulation as they are observed in ever improving observations and realistic numerical simulations. A closer look at this problem also explains the so-called 'convection conundrum': the discrepancy between results from helioseismic measurements of subsurface flows' on the one hand and 'whole convection zone' simulations on the other. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-09-28 Nestor Espinoza (***DIFFERENT DATE AND PLACE!!***) 2023-10-06 Matilde Mingozzi 2023-10-13 Guillaume Guiglion You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Sep 25 04:13:29 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 25 Sep 2023 02:13:29 +0000 Subject: [Astronomy seminar] =?windows-1252?q?Astronomy_departmental_semin?= =?windows-1252?q?ar_Thursday_September_28th_=28**DIFFERENT_DATE_AND_PLACE?= =?windows-1252?q?**=29_at_10=3A30am_-_N=E9stor_Espinoza_=28Space_Telescop?= =?windows-1252?q?e_Science_Institute_-_Johns_Hopkins_University=29?= Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Thursday September 28th at 10:30am in room FB42 (AlbaNova building, 4th floor, check a map in: https://www.kth.se/places/room/id/d0adc673-3b21-4590-8e07-4995c3c449df) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ——————————— Speaker: Néstor Espinoza (Space Telescope Science Institute - Johns Hopkins University) Title: Exploring new frontiers in exoplanetary science with JWST https://indico.fysik.su.se/e/nestor-espinoza Abstract: The scientific results from the first year of scientific operations of the James Webb Space Telescope (JWST) has delivered the promise: it is humanity's sharpest eye to look at the infrared Universe. From being able to detect the faint light of the first galaxies to being able to characterize the atmospheres of Earth-sized worlds, the observatory's unique capabilities is allowing it to perform a wide range of exciting science, that is already changing our perspectives on how we understand our Universe. In this talk, I will introduce the new frontiers JWST is exploring in the field of exoplanetary science during this very first year of scientific operations, with a special focus on transiting exoplanets. Through some early results on new dimensions being explored for gas giant exoplanets, as well as prospects for the first looks at the atmospheres and surfaces of small, rocky exoplanets, I will show how JWST is changing our understanding of planetary systems in the cosmos, and how this could allow us to put our own Solar System in this exoplanetary context. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-10-06 Matilde Mingozzi 2023-10-13 Guillaume Guiglion 2023-10-20 TBD 2023-10-27 Maryam Saberi 2023-11-03 TBD 2023-11-10 Alberto Saldana Lopez 2023-11-17 TBD 2023-11-24 Aline Chu 2023-12-01 TBD You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Thu Sep 28 08:21:28 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Thu, 28 Sep 2023 06:21:28 +0000 Subject: [Astronomy seminar] =?windows-1252?q?Reminder=3A_Astronomy_depart?= =?windows-1252?q?mental_seminar_on_Thursday_September_28th_=28**DIFFERENT?= =?windows-1252?q?_DATE_AND_PLACE**=29_at_10=3A30am_-_N=E9stor_Espinoza_?= =?windows-1252?q?=28Space_Telescope_Science_Institute_-_Johns_Hopkins_Uni?= =?windows-1252?q?versity=29?= Message-ID: Dear all, This is a reminder of the next SU astronomy departmental seminar that will take place today Thursday, in about 130 minutes, at 10:30am in room FB42 (AlbaNova building, 4th floor, check: https://www.kth.se/places/room/id/d0adc673-3b21-4590-8e07-4995c3c449df for a map) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). As usual, we encourage you to attend in person if possible. ——————————— Speaker: Néstor Espinoza (Space Telescope Science Institute - Johns Hopkins University) Title: Exploring new frontiers in exoplanetary science with JWST https://indico.fysik.su.se/e/nestor-espinoza Abstract: The scientific results from the first year of scientific operations of the James Webb Space Telescope (JWST) has delivered the promise: it is humanity's sharpest eye to look at the infrared Universe. From being able to detect the faint light of the first galaxies to being able to characterize the atmospheres of Earth-sized worlds, the observatory's unique capabilities is allowing it to perform a wide range of exciting science, that is already changing our perspectives on how we understand our Universe. In this talk, I will introduce the new frontiers JWST is exploring in the field of exoplanetary science during this very first year of scientific operations, with a special focus on transiting exoplanets. Through some early results on new dimensions being explored for gas giant exoplanets, as well as prospects for the first looks at the atmospheres and surfaces of small, rocky exoplanets, I will show how JWST is changing our understanding of planetary systems in the cosmos, and how this could allow us to put our own Solar System in this exoplanetary context. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-10-06 Matilde Mingozzi 2023-10-13 Guillaume Guiglion 2023-10-20 Adam Rains 2023-10-27 Maryam Saberi 2023-11-03 TBD 2023-11-10 Alberto Saldana Lopez 2023-11-17 TBD 2023-11-24 Aline Chu 2023-12-01 TBD You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that we are currently experiencing some technical issues with the calendar and it is currently not displaying some of the incoming events) (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Oct 2 17:38:55 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 2 Oct 2023 17:38:55 +0200 Subject: [Astronomy seminar] Astronomy departmental seminar Friday October 6 at 10:30am - Matilde Mingozzi (Space Telescope Science Institute) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday October 6 at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ——————————— Speaker: Matilde Mingozzi (Space Telescope Science Institute) Title: The study of Interstellar Medium diagnostics in local galaxies to Interpret the Reionization-Era Event: https://indico.fysik.su.se/e/matilde-mingozzi Abstract: Rest-frame UV spectra play a key role in the understanding of massive stellar populations, chemical evolution, feedback processes, and reionization. Indeed, in the current JWST era, the UV spectroscopic frontier has been pushed to higher redshifts than ever before, to finally reveal the first galaxies in the distant Universe. In this context, the HST COS Legacy Archive Spectroscopic SurveY (CLASSY) provides the first high-quality, high-resolution and broad-wavelength range catalogue of 45 local star-forming galaxies (SFGs) in the rest-frame UV (1150 −2000 Å) to investigate their stellar and gas properties. The sample is representative of SFGs across all redshifts, including extremely metal-poor objects similar to reionization-era systems. Hence, CLASSY provides the ideal UV atlas with which we can tailor a complete UV diagnostic toolkit to explore the interstellar medium (ISM) properties (i.e., density, temperature, gas-phase metallicity, ionization parameter). In this talk I will present such a toolkit, obtained from the analysis of the main emission lines of CLASSY spectra and the comparison with well-known optical diagnostics. We also compared our measurements with state-of-the-art photoionization models, to provide the best diagnostics plots to identify the main source of ionization. Overall, CLASSY and our UV toolkit can be crucial to interpret the earliest galaxies revealed with JWST. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-10-13 Guillaume Guiglion 2023-10-20 Adam Rains 2023-10-27 Maryam Saberi 2023-11-03 TBD 2023-11-10 Alberto Saldana Lopez 2023-11-17 TBD 2023-11-24 Aline Chu 2023-12-01 TBD You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that we are currently experiencing some technical issues with the calendar and it is currently not displaying some of the incoming events) (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Oct 6 09:31:44 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 6 Oct 2023 09:31:44 +0200 Subject: [Astronomy seminar] Reminder: Astronomy departmental seminar Friday October 6 at 10:30am - Matilde Mingozzi (Space Telescope Science Institute) Message-ID: Dear all, This is a reminder of the weekly SU astronomy departmental seminar that will take place in about 59 minutes, *at 10:30am in room FC61* (AlbaNova building, 6th floor) *and on zoom* (https://stockholmuniversity.zoom.us/s/61002076352). As usual, we encourage you to attend in person if possible. ——————————— Speaker: Matilde Mingozzi (Space Telescope Science Institute) Title: The study of Interstellar Medium diagnostics in local galaxies to Interpret the Reionization-Era Event: https://indico.fysik.su.se/e/matilde-mingozzi Abstract: Rest-frame UV spectra play a key role in the understanding of massive stellar populations, chemical evolution, feedback processes, and reionization. Indeed, in the current JWST era, the UV spectroscopic frontier has been pushed to higher redshifts than ever before, to finally reveal the first galaxies in the distant Universe. In this context, the HST COS Legacy Archive Spectroscopic SurveY (CLASSY) provides the first high-quality, high-resolution and broad-wavelength range catalogue of 45 local star-forming galaxies (SFGs) in the rest-frame UV (1150 −2000 Å) to investigate their stellar and gas properties. The sample is representative of SFGs across all redshifts, including extremely metal-poor objects similar to reionization-era systems. Hence, CLASSY provides the ideal UV atlas with which we can tailor a complete UV diagnostic toolkit to explore the interstellar medium (ISM) properties (i.e., density, temperature, gas-phase metallicity, ionization parameter). In this talk I will present such a toolkit, obtained from the analysis of the main emission lines of CLASSY spectra and the comparison with well-known optical diagnostics. We also compared our measurements with state-of-the-art photoionization models, to provide the best diagnostics plots to identify the main source of ionization. Overall, CLASSY and our UV toolkit can be crucial to interpret the earliest galaxies revealed with JWST. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-10-13    Guillaume Guiglion 2023-10-20    Adam Rains 2023-10-27    Maryam Saberi 2023-11-03    TBA 2023-11-10    Alberto Saldana Lopez 2023-11-17    TBA 2023-11-24    Aline Chu 2023-12-01    Heitor Ernandes 2023-12-08    Quentin Perceval Xavier Pognan You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Oct 9 13:49:12 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 9 Oct 2023 11:49:12 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday October 13 at 10:30am - Guillaume Guiglion (ZAH/ LSW, MPIA) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday October 13 at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ——————————— Speaker: Guillaume Guiglion (ZAH/ LSW, MPIA) Title: Machine-learning for stellar spectroscopy: from RAVE to Gaia-RVS & 4MOST Event: https://indico.fysik.su.se/e/guillaume-guiglion Abstract: In this seminar, I will present recent developments in the field of machine-learning applied to stellar spectra in the context of large scale spectroscopic surveys, such as Gaia-ESO and RAVE. I will particularly focus on Gaia DR3, which provided the community with approximately one million RVS spectra covering the CaII triplet region. One third of the spectra have a signal-to-noise ratio from 15 to 25 per pixel. I will demonstrate that precise parametrization can be achieved for such a type of dataset by using machine-learning and the full power of the Gaia data. I will present a new approach in the form of a hybrid Convolutional Neural-Network (CNN) to derive atmospheric parameters (Teff, log(g), and [M/H]) and chemical abundances ([Fe/H] and [α/M]). Our CNN is designed to effectively combine the Gaia DR3 RVS spectra, photometry (G, Bp, Rp), parallaxes, and XP coefficients and is able to extract additional information from non-spectral inputs to supplement the limited spectral coverage of the RVS spectra. We manage to characterize the [α/M] − [M/H] bimodality from the inner regions to the outer part of the Milky Way, which has never been characterized using RVS spectra or similar datasets. I will also discuss the benefits of using CNNs for future large scale spectroscopic surveys such as 4MOST. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-10-20 Adam Rains 2023-10-27 Maryam Saberi 2023-11-03 TBA 2023-11-10 Alberto Saldana Lopez 2023-11-17 TBA 2023-11-24 Aline Chu 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Oct 13 10:09:04 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 13 Oct 2023 08:09:04 +0000 Subject: [Astronomy seminar] Reminder: Astronomy departmental seminar Friday October 13 at 10:30am - Guillaume Guiglion (ZAH/ LSW, MPIA) Message-ID: Dear all, This is a reminder of the weekly SU astronomy departmental seminar that will take place in about 20 minutes, at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). As usual, we encourage you to attend in person if possible. ——————————— Speaker: Guillaume Guiglion (ZAH/ LSW, MPIA) Title: Machine-learning for stellar spectroscopy: from RAVE to Gaia-RVS & 4MOST Event: https://indico.fysik.su.se/e/guillaume-guiglion Abstract: In this seminar, I will present recent developments in the field of machine-learning applied to stellar spectra in the context of large scale spectroscopic surveys, such as Gaia-ESO and RAVE. I will particularly focus on Gaia DR3, which provided the community with approximately one million RVS spectra covering the CaII triplet region. One third of the spectra have a signal-to-noise ratio from 15 to 25 per pixel. I will demonstrate that precise parametrization can be achieved for such a type of dataset by using machine-learning and the full power of the Gaia data. I will present a new approach in the form of a hybrid Convolutional Neural-Network (CNN) to derive atmospheric parameters (Teff, log(g), and [M/H]) and chemical abundances ([Fe/H] and [α/M]). Our CNN is designed to effectively combine the Gaia DR3 RVS spectra, photometry (G, Bp, Rp), parallaxes, and XP coefficients and is able to extract additional information from non-spectral inputs to supplement the limited spectral coverage of the RVS spectra. We manage to characterize the [α/M] − [M/H] bimodality from the inner regions to the outer part of the Milky Way, which has never been characterized using RVS spectra or similar datasets. I will also discuss the benefits of using CNNs for future large scale spectroscopic surveys such as 4MOST. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-10-20 Adam Rains 2023-10-27 Maryam Saberi 2023-11-03 TBA 2023-11-10 Alberto Saldana Lopez 2023-11-17 TBA 2023-11-24 Aline Chu 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Mon Oct 16 19:10:58 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 16 Oct 2023 17:10:58 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday October 20 at 10:30am - Adam Rains (UU) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday October 20 at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ——————————— Speaker: Adam Rains Title: Exploring Optical Cool Dwarf Chemistry with Both Data-Driven and Physical Models Event: https://indico.fysik.su.se/e/adam-rains Abstract: Detailed chemical studies of Solar-type stars have long been routine in stellar astrophysics, making possible studies in Galactic chemodynamics and exoplanet demographics. However, similar understanding of the chemistry of M and late-K dwarfs---the most common stars in the Galaxy and most likely to host planets---has been greatly hampered both observationally and theoretically by the complex molecular chemistry of their atmospheres. During this talk I will discuss the importance of well-constrained cool dwarf benchmark stars, how we can take advantage of trends in Galactic chemodynamics as applied to cool dwarf chemistry, and how these both relate to my recent work exploring the the spectra and chemistry of these stars at optical wavelengths using both data-driven and physical models. In particular, I demonstrate the ability of a data-driven Cannon model to successfully recover [Fe/H] and [Ti/Fe] from low-medium resolution optical spectra, investigate the sensitivity of MARCS model spectra to a broader set of chemical abundances to inform future work, and provide insight into the reliability of MARCS models for cool dwarf stars. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-10-27 Maryam Saberi 2023-11-03 TBA 2023-11-10 Alberto Saldana Lopez 2023-11-17 TBA 2023-11-24 Aline Chu 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Oct 20 10:08:06 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 20 Oct 2023 10:08:06 +0200 Subject: [Astronomy seminar] Reminder: Astronomy departmental seminar Friday October 20 at 10:30am - Adam Rains (UU) Message-ID: Dear all, This is a reminder of the weekly SU astronomy departmental seminar that will take place in about 22 minutes, at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). As usual, we encourage you to attend in person if possible. ——————————— Speaker: Adam Rains Title: Exploring Optical Cool Dwarf Chemistry with Both Data-Driven and Physical Models Event: https://indico.fysik.su.se/e/adam-rains Abstract: Detailed chemical studies of Solar-type stars have long been routine in stellar astrophysics, making possible studies in Galactic chemodynamics and exoplanet demographics. However, similar understanding of the chemistry of M and late-K dwarfs---the most common stars in the Galaxy and most likely to host planets---has been greatly hampered both observationally and theoretically by the complex molecular chemistry of their atmospheres. During this talk I will discuss the importance of well-constrained cool dwarf benchmark stars, how we can take advantage of trends in Galactic chemodynamics as applied to cool dwarf chemistry, and how these both relate to my recent work exploring the the spectra and chemistry of these stars at optical wavelengths using both data-driven and physical models. In particular, I demonstrate the ability of a data-driven Cannon model to successfully recover [Fe/H] and [Ti/Fe] from low-medium resolution optical spectra, investigate the sensitivity of MARCS model spectra to a broader set of chemical abundances to inform future work, and provide insight into the reliability of MARCS models for cool dwarf stars. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-10-27 Maryam Saberi 2023-11-03 TBA 2023-11-10 Alberto Saldana Lopez 2023-11-17 TBA 2023-11-24 Aline Chu 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 From seminars-announce.astro-at-su.se at lists.su.se Mon Oct 23 12:02:19 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 23 Oct 2023 10:02:19 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday October 27 at 10:30am - Maryam Saberi (RoCS-UiO) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday October 27 at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ——————————— Speaker: Maryam Saberi Title: Tracing the impact of Evolved Stars on the Galactic Chemical enrichment (ESGC) Event: https://indico.fysik.su.se/e/maryam-saberi Abstract: In this presentation, I will discuss my ESGC project, which was recently awarded funding from the Research Council of Norway. The primary focus of my project is on evolved stars and their impact on enriching the chemical composition of interstellar mediums and galaxies. I will begin by providing an introduction to evolved stars and the chemistry active in their outflow. Solar-type stars eject a substantial amount of heavy elements and dust particles to the interstellar medium through strong stellar winds at late phases of stellar evolution, known as the asymptotic giant branch (AGB) phase, and therefore significantly influence the chemical composition of galaxies. In ESGC project, I aim to target two main gaps in our knowledge that can be significantly advanced with current observational facilities, new laboratory molecular data, and upgraded chemical models. These gaps concern the role of AGB stars in the production of fluorine in our Galaxy, which is an essential element for the maintenance of solidity in our bones and teeth, and the impact of a chromospheric UV radiation field on the chemistry and dust-formation process around AGB stars. Through this project, I aim to create a more realistic picture of the recycled materials and stardust from evolved stars by considering the impact of internal UV radiation in the chemical models. Finally, I will outline the observational and simulation approaches I am planning to use to achieve the main objectives of the project and highlighting the unique opportunities associated with each approach. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-11-03 TBA 2023-11-10 Alberto Saldana Lopez 2023-11-17 TBA 2023-11-24 Aline Chu 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Oct 27 09:52:30 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 27 Oct 2023 09:52:30 +0200 Subject: [Astronomy seminar] Reminder: Astronomy departmental seminar Friday October 27 at 10:30am - Maryam Saberi (RoCS-UiO) Message-ID: Dear all, This is a reminder of the weekly SU astronomy departmental seminar that will take place in about 38 minutes, at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). As usual, we encourage you to attend in person if possible. ——————————— Speaker: Maryam Saberi Title: Tracing the impact of Evolved Stars on the Galactic Chemical enrichment (ESGC) Event: https://indico.fysik.su.se/e/maryam-saberi Abstract: In this presentation, I will discuss my ESGC project, which was recently awarded funding from the Research Council of Norway. The primary focus of my project is on evolved stars and their impact on enriching the chemical composition of interstellar mediums and galaxies. I will begin by providing an introduction to evolved stars and the chemistry active in their outflow. Solar-type stars eject a substantial amount of heavy elements and dust particles to the interstellar medium through strong stellar winds at late phases of stellar evolution, known as the asymptotic giant branch (AGB) phase, and therefore significantly influence the chemical composition of galaxies. In ESGC project, I aim to target two main gaps in our knowledge that can be significantly advanced with current observational facilities, new laboratory molecular data, and upgraded chemical models. These gaps concern the role of AGB stars in the production of fluorine in our Galaxy, which is an essential element for the maintenance of solidity in our bones and teeth, and the impact of a chromospheric UV radiation field on the chemistry and dust-formation process around AGB stars. Through this project, I aim to create a more realistic picture of the recycled materials and stardust from evolved stars by considering the impact of internal UV radiation in the chemical models. Finally, I will outline the observational and simulation approaches I am planning to use to achieve the main objectives of the project and highlighting the unique opportunities associated with each approach. ——————————— We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-11-03 Linn Boldt-Christmas 2023-11-10 Alberto Saldana Lopez 2023-11-17 TBA 2023-11-24 Aline Chu 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ——————————— Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 From seminars-announce.astro-at-su.se at lists.su.se Mon Oct 30 12:12:23 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 30 Oct 2023 11:12:23 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday November 3 at 10:30am - Linn Boldt-Christmas (Uppsala University) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday November 3 at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ___________________ Speaker: Linn Boldt-Christmas (Uppsala University) Title: The Exoplanet Exposure Triangle: Optimising spectroscopic observations of transiting exoplanets’ atmospheres Event: https://indico.fysik.su.se/e/linn-boldt-christmas Abstract: Transiting exoplanets provide opportunities for us to observe their atmospheres and to analyse them using spectroscopy. As the characterisation of exoplanetary atmospheres relies on the detection of spectrally resolved features, analysis can be improved with high signal-to-noise ratios (SNR) that are possible to obtain today with modern spectrographs. However, obtaining high SNR through adjusting exposure times comes with a trade-off. A higher cadence of several, shorter exposures minimises the spectral feature smearing that arises due to the continuously changing radial velocity of the planet; but a lower cadence of fewer, longer exposures collects more photons with reduced overheads and readout noise, enhancing the SNR of each observation. As such, there is a need to establish what the optimal compromise is between the SNR and time resolution for a given target. In this talk, I will present the results of our search for this compromise using simulated VLT/CRIRES+ spectra and cross-correlation analysis, together with our conclusions which form recommendations for observers that are planning studies of exoplanetary atmospheres using ground-based instrumentation. ___________________ We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-11-10 Alberto Saldana Lopez 2023-11-17 TBA 2023-11-24 Aline Chu 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan --- Winter break --- You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ___________________ Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Nov 3 09:34:53 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 3 Nov 2023 09:34:53 +0100 Subject: [Astronomy seminar] Reminder: Astronomy departmental seminar Friday November 3 at 10:30am - Linn Boldt-Christmas (Uppsala University) Message-ID: Dear all, This is a reminder of the weekly SU astronomy departmental seminar that will take place in about 55 minutes, at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). As usual, we encourage you to attend in person if possible. ——————————— Speaker: Linn Boldt-Christmas (Uppsala University) Title: The Exoplanet Exposure Triangle: Optimising spectroscopic observations of transiting exoplanets’ atmospheres Event: https://indico.fysik.su.se/e/linn-boldt-christmas Abstract: Transiting exoplanets provide opportunities for us to observe their atmospheres and to analyse them using spectroscopy. As the characterisation of exoplanetary atmospheres relies on the detection of spectrally resolved features, analysis can be improved with high signal-to-noise ratios (SNR) that are possible to obtain today with modern spectrographs. However, obtaining high SNR through adjusting exposure times comes with a trade-off. A higher cadence of several, shorter exposures minimises the spectral feature smearing that arises due to the continuously changing radial velocity of the planet; but a lower cadence of fewer, longer exposures collects more photons with reduced overheads and readout noise, enhancing the SNR of each observation. As such, there is a need to establish what the optimal compromise is between the SNR and time resolution for a given target. In this talk, I will present the results of our search for this compromise using simulated VLT/CRIRES+ spectra and cross-correlation analysis, together with our conclusions which form recommendations for observers that are planning studies of exoplanetary atmospheres using ground-based instrumentation. ___________________ We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-11-10 *Cancelled* 2023-11-17 Alberto Saldana Lopez 2023-11-24 Aline Chu 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan --- Winter break --- You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ___________________ Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 From seminars-announce.astro-at-su.se at lists.su.se Thu Nov 9 13:54:27 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Thu, 9 Nov 2023 13:54:27 +0100 Subject: [Astronomy seminar] No astronomy departmental seminar on Friday November 10 Message-ID: Dear all, This Friday (November 10) there will be no astronomy departmental seminar and we will have to wait until November 17 for the seminar of the newly arrived Alberto Saldana Lopez. We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-11-17 Alberto Saldana Lopez 2023-11-24 Aline Chu 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan --- Winter break --- You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ___________________ Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 From seminars-announce.astro-at-su.se at lists.su.se Mon Nov 13 11:21:32 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 13 Nov 2023 10:21:32 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday November 17 at 10:30am - Alberto Saldana Lopez (Stockholm University) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday November 17 at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ___________________ Speaker: Alberto Saldana Lopez (Stockholm University) Title: A low-redshift look to reionization with star-forming galaxies Event: https://indico.fysik.su.se/e/alberto-saldana-lopez Abstract: One of the current hot topics in galaxy evolution is the so-called Cosmic Reionization, the last major cosmic phase by which the Universe transitioned from a neutral to a (mostly) ionized state, happening around z = 6-9. The main responsible sources for reionization are still under debate, but star-forming galaxies seem to be the likeliest due to their high number density at early epochs respect to Active Galactic Nuclei. However, directly probing ionizing (also called Lyman Continuum, LyC) radiation from galaxies at the Epoch of Reionization is difficult, since the escaping photons are likely absorbed by the remaining neutral gas in the intergalactic medium (IGM). Therefore, in order to study the role of star-forming galaxies during Reionization, we need to rely on indirect indicators of such emergent LyC radiation. The low-redshift Universe offers a unique window to study the properties of LyC-emitting galaxies, since the IGM attenuation is negligible and, at the same time, a full suite of multi-wavelength observations is available both from space and the ground. Recent HST campaigns such as the Low-Redshift Lyman Continuum Survey (LzLCS) has nearly tripled the number of LyC detections at low-redshift. The LzLCS has revealed that compact star formation, high ionization parameters, strong and narrow LyA emission, low dust-attenuation and the presence of weak absorption lines seem to characterize the spectra of the strongest LyC emitters. In this talk, I will present some of the main results of the LzLCS and explain how this data set has changed our understanding of the mechanisms for LyC escape. We will also discuss the implications of these results for the high redshift community in the JWST era. ___________________ We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-11-24 Aline Chu 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan --- Winter break --- You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ___________________ Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Nov 17 10:07:34 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 17 Nov 2023 10:07:34 +0100 Subject: [Astronomy seminar] Reminder: Astronomy departmental seminar Friday November 17 at 10:30am - Alberto Saldana Lopez (Stockholm University) Message-ID: Dear all, This is a reminder of the weekly SU astronomy departmental seminar that will take place in about 23 minutes, at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). As usual, we encourage you to attend in person if possible. ___________________ Speaker: Alberto Saldana Lopez (Stockholm University) Title: A low-redshift look to reionization with star-forming galaxies Event: https://indico.fysik.su.se/e/alberto-saldana-lopez Abstract: One of the current hot topics in galaxy evolution is the so-called Cosmic Reionization, the last major cosmic phase by which the Universe transitioned from a neutral to a (mostly) ionized state, happening around z = 6-9. The main responsible sources for reionization are still under debate, but star-forming galaxies seem to be the likeliest due to their high number density at early epochs respect to Active Galactic Nuclei. However, directly probing ionizing (also called Lyman Continuum, LyC) radiation from galaxies at the Epoch of Reionization is difficult, since the escaping photons are likely absorbed by the remaining neutral gas in the intergalactic medium (IGM). Therefore, in order to study the role of star-forming galaxies during Reionization, we need to rely on indirect indicators of such emergent LyC radiation. The low-redshift Universe offers a unique window to study the properties of LyC-emitting galaxies, since the IGM attenuation is negligible and, at the same time, a full suite of multi-wavelength observations is available both from space and the ground. Recent HST campaigns such as the Low-Redshift Lyman Continuum Survey (LzLCS) has nearly tripled the number of LyC detections at low-redshift. The LzLCS has revealed that compact star formation, high ionization parameters, strong and narrow LyA emission, low dust-attenuation and the presence of weak absorption lines seem to characterize the spectra of the strongest LyC emitters. In this talk, I will present some of the main results of the LzLCS and explain how this data set has changed our understanding of the mechanisms for LyC escape. We will also discuss the implications of these results for the high redshift community in the JWST era. ___________________ We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-11-24 Aline Chu 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan --- Winter break --- You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ___________________ Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Tue Nov 21 11:21:08 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Tue, 21 Nov 2023 10:21:08 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday November 24 at 10:30am - Aline Chu (Stockholm University) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday November 24 at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ___________________ Speaker: Aline Chu (Stockholm University) Title: Evolution of the properties of brightest galaxies of clusters and groups since the last 10 Gyrs Event: https://indico.fysik.su.se/e/aline-chu Abstract: Galaxy clusters are the largest gravitationally bound structures of the Universe. At the center of these clusters reside the most massive galaxies observable today, Brightest Cluster Galaxies (BCGs). BCGs are the final products of 10 Gyrs of consecutive galactic mergers in the densest regions of the cosmic web. They are excellent tracers of cluster formation, and ideal to study the impact of environmental processes on galactic formation. The characterization of the physical properties of BCGs is important to obtain better knowledge of these galaxies. We have built new catalogues of BCGs which have allowed us to conduct a deeper analysis of the formation of BCGs, thanks to the bigger statistics we reached. We find BCGs have shown a lack of evolution of their sizes and luminosities in the last 10 Gyrs, hinting at an earlier formation epoch and absence of recent significant growth. Their structural properties, however, may have changed over time, as hinted by the detection of an envelope only at recent epoch. We also compare the evolution of BCGs and the brightest galaxies of less dense environments such as galaxy groups or more special systems such as fossil groups (FGs). We find that brightest galaxies of FGs evolve more similarly to BCGs of clusters than brightest galaxies of normal groups of galaxies, as inferred from their Kormendy relations. These results may be confirmed with the future Rubin-LSST survey which will observe the entire southern sky at even further lookback times, providing us with images of unprecedented depth. ___________________ We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan --- Winter break --- You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ___________________ Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Nov 24 09:55:56 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 24 Nov 2023 09:55:56 +0100 Subject: [Astronomy seminar] Reminder: Astronomy departmental seminar Friday November 24 at 10:30am - Aline Chu (Stockholm University) Message-ID: Dear all, This is a reminder of the weekly SU astronomy departmental seminar that will take place in about 34 minutes, at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). As usual, we encourage you to attend in person if possible. ___________________ Speaker: Aline Chu (Stockholm University) Title: Evolution of the properties of brightest galaxies of clusters and groups since the last 10 Gyrs Event: https://indico.fysik.su.se/e/aline-chu Abstract: Galaxy clusters are the largest gravitationally bound structures of the Universe. At the center of these clusters reside the most massive galaxies observable today, Brightest Cluster Galaxies (BCGs). BCGs are the final products of 10 Gyrs of consecutive galactic mergers in the densest regions of the cosmic web. They are excellent tracers of cluster formation, and ideal to study the impact of environmental processes on galactic formation. The characterization of the physical properties of BCGs is important to obtain better knowledge of these galaxies. We have built new catalogues of BCGs which have allowed us to conduct a deeper analysis of the formation of BCGs, thanks to the bigger statistics we reached. We find BCGs have shown a lack of evolution of their sizes and luminosities in the last 10 Gyrs, hinting at an earlier formation epoch and absence of recent significant growth. Their structural properties, however, may have changed over time, as hinted by the detection of an envelope only at recent epoch. We also compare the evolution of BCGs and the brightest galaxies of less dense environments such as galaxy groups or more special systems such as fossil groups (FGs). We find that brightest galaxies of FGs evolve more similarly to BCGs of clusters than brightest galaxies of normal groups of galaxies, as inferred from their Kormendy relations. These results may be confirmed with the future Rubin-LSST survey which will observe the entire southern sky at even further lookback times, providing us with images of unprecedented depth. ___________________ We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-12-01 Heitor Ernandes 2023-12-08 Quentin Perceval Xavier Pognan --- Winter break --- You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ___________________ Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 From seminars-announce.astro-at-su.se at lists.su.se Mon Nov 27 20:45:48 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 27 Nov 2023 19:45:48 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday December 1 at 10:30am - Heitor Ernandes (Lund University) Message-ID: Dear all, The next SU astronomy departmental seminar will take place on Friday December 1 at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ___________________ Speaker: Heitor Ernandes (Lund University) Title: The Bright Future of Ground-Based Near-UV Spectroscopy for R-rich Stars Event: https://indico.fysik.su.se/e/heitor-ernandes Abstract: Stars that present an enhancement in r-process elements are rare objects in the sky. Only 72 stars are categorised as r-II stars, which show a high level of enhancement in the elements such as Europium. They are the key to understanding the astrophysical site where these heavy elements can be synthesised and the time scale of these events. However, to have a complete picture of these r-process creation sites, we need the complete abundance pattern for chemically peculiar stars such as actinide boost and CEMP stars. To access all this information, it is needed to observe under 4000 Å. However, this region is heavily affected by atmosphere absorption. Overcoming this challenge, the forthcoming generation of instruments, exemplified by VLT-CUBES, holds significant promise for refining near-UV observational capabilities from the ground. ___________________ We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-12-08 Quentin Perceval Xavier Pognan --- Winter break --- You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ___________________ Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Dec 1 09:56:39 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 1 Dec 2023 09:56:39 +0100 Subject: [Astronomy seminar] Reminder: Astronomy departmental seminar Friday December 1 at 10:30am - Heitor Ernandes (Lund University) Message-ID: Dear all, This is a reminder of the weekly SU astronomy departmental seminar that will take place in about 33 minutes, at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). As usual, we encourage you to attend in person if possible. ___________________ Speaker: Heitor Ernandes (Lund University) Title: The Bright Future of Ground-Based Near-UV Spectroscopy for R-rich Stars Event: https://indico.fysik.su.se/e/heitor-ernandes Abstract: Stars that present an enhancement in r-process elements are rare objects in the sky. Only 72 stars are categorised as r-II stars, which show a high level of enhancement in the elements such as Europium. They are the key to understanding the astrophysical site where these heavy elements can be synthesised and the time scale of these events. However, to have a complete picture of these r-process creation sites, we need the complete abundance pattern for chemically peculiar stars such as actinide boost and CEMP stars. To access all this information, it is needed to observe under 4000 Å. However, this region is heavily affected by atmosphere absorption. Overcoming this challenge, the forthcoming generation of instruments, exemplified by VLT-CUBES, holds significant promise for refining near-UV observational capabilities from the ground. ___________________ We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: 2023-12-08 Quentin Perceval Xavier Pognan --- Winter break --- You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ___________________ Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 From seminars-announce.astro-at-su.se at lists.su.se Mon Dec 4 22:08:26 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Mon, 4 Dec 2023 21:08:26 +0000 Subject: [Astronomy seminar] Astronomy departmental seminar Friday December 8 at 10:30am - Quentin Perceval Xavier Pognan (Stockholm University) Message-ID: Dear all, The next SU astronomy departmental seminar (last of 2023) will take place on Friday December 8 at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). ___________________ Speaker: Quentin Perceval Xavier Pognan (Stockholm University) Title: Modelling Kilonova Spectra with NLTE Physics Event: https://indico.fysik.su.se/e/quentin-pognan Abstract: The rapid neutron capture (r-process) has long been theorised to produce approximately half of the elements heavier than iron in the Universe. A promising site of r-process nucleosynthesis is believed to be neutron star (NS) mergers. In 2017, the first ever binary NS merger was observed thoroughly in gravitational wave emission, as well as in a broad-band electromagnetic (EM) follow up. This EM follow up observed the famous kilonova (KN) AT2017gfo, powered by the radioactive decay of unstable r-process isotopes created in the merger ejecta. Since these transients are powered by r-process species, it follows that the analysis of features in KN emission can lead to the identification of elements produced in NS mergers, and place constraints on their origins in the Universe. A promising approach to do so is by spectral analysis of the emergent KN spectra. However, this requires detailed spectral models which can explain the diverse, complex features in the observed emission. In particular, due to the rapid expansion of merger ejecta moving at velocities of ~ 0.1 - 0.3c, the KN quickly moves away from the photospheric phase, where Local Thermodynamic Equilibrium (LTE) physics apply, into the non-LTE regime. In this regime, the gas state of the ejecta cannot be determined using the Saha-Boltzmann equations, and must instead be found by solving rate equations coupling diverse non-thermal processes, which greatly increases the complexity of the problem. In this talk, I will go over the spectral modelling of KNe in the NLTE regime, firstly introducing the context and difficulties of this approach, and then focussing on recent works and results making use of NLTE radiative transfer codes to this end. ___________________ We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: --- Winter break --- You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ___________________ Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: From seminars-announce.astro-at-su.se at lists.su.se Fri Dec 8 09:54:01 2023 From: seminars-announce.astro-at-su.se at lists.su.se (Astronomy seminar announcements) Date: Fri, 8 Dec 2023 08:54:01 +0000 Subject: [Astronomy seminar] Reminder: Astronomy departmental seminar Friday December 8 at 10:30am - Quentin Perceval Xavier Pognan (Stockholm University) Message-ID: Dear all, This is a reminder of the weekly SU astronomy departmental seminar that will take place in about 37 minutes, at 10:30am in room FC61 (AlbaNova building, 6th floor) and on zoom (https://stockholmuniversity.zoom.us/s/61002076352). As usual, we encourage you to attend in person if possible. ___________________ Speaker: Quentin Perceval Xavier Pognan (Stockholm University) Title: Modelling Kilonova Spectra with NLTE Physics Event: https://indico.fysik.su.se/e/quentin-pognan Abstract: The rapid neutron capture (r-process) has long been theorised to produce approximately half of the elements heavier than iron in the Universe. A promising site of r-process nucleosynthesis is believed to be neutron star (NS) mergers. In 2017, the first ever binary NS merger was observed thoroughly in gravitational wave emission, as well as in a broad-band electromagnetic (EM) follow up. This EM follow up observed the famous kilonova (KN) AT2017gfo, powered by the radioactive decay of unstable r-process isotopes created in the merger ejecta. Since these transients are powered by r-process species, it follows that the analysis of features in KN emission can lead to the identification of elements produced in NS mergers, and place constraints on their origins in the Universe. A promising approach to do so is by spectral analysis of the emergent KN spectra. However, this requires detailed spectral models which can explain the diverse, complex features in the observed emission. In particular, due to the rapid expansion of merger ejecta moving at velocities of ~ 0.1 - 0.3c, the KN quickly moves away from the photospheric phase, where Local Thermodynamic Equilibrium (LTE) physics apply, into the non-LTE regime. In this regime, the gas state of the ejecta cannot be determined using the Saha-Boltzmann equations, and must instead be found by solving rate equations coupling diverse non-thermal processes, which greatly increases the complexity of the problem. In this talk, I will go over the spectral modelling of KNe in the NLTE regime, firstly introducing the context and difficulties of this approach, and then focussing on recent works and results making use of NLTE radiative transfer codes to this end. ___________________ We look forward to seeing many of you there. Thanks! Adur and Adélaïde Upcoming Events: --- Winter break --- You can subscribe to the seminars calendar in: https://ttt.astro.su.se/ical/astro-seminars.ics (Please note that calendar can be subject to updates) ___________________ Join Zoom Meeting: https://stockholmuniversity.zoom.us/s/61002076352 Meeting ID: 610 0207 6352 -------------- next part -------------- An HTML attachment was scrubbed... URL: