From andre.schneider at astro.su.se Tue Feb 5 12:23:04 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Tue, 5 Feb 2019 11:23:04 +0000 Subject: [Okc-wp4] EO Meeting on Feb 7 Message-ID: <7c3a75df1f2047ca87a192c6fb0eb5db@astro.su.se> Dear all, our first EO meeting of 2019 will be this Thursday Feb 7 at 13:00 (KTH meeting room on the 5th floor). Joonas Nättilä will give the following talk: Title: Magnetically-dominated collisionless plasma flows in neutron star atmospheres Abstract: I will discuss collisionless plasma instabilities operating on magnetically-dominated flows in neutron star atmospheres. We define a criteria for out-of-resonance two-stream instability to be operational in the stratified atmosphere. Our theoretical findings are then confirmed with high-resolution, first-principles relativistic Vlasov-Maxwell simulations. This allows us to study the subsequent non-linear turbulent evolution of the system. We find a new plasma mechanism that reprocesses the incoming mildly-relativistic beams: The incoming beams are slowed down, heated up, but not brought to full halt either. Ultra-relativistic beams are still capable of penetrating into the star unaffected. This implies that diluted free-falling accretion flows into neutron stars are always reprocessed in the uppermost layers of the star's atmosphere before entering the particle-collision-dominated layers below. This beam-atmosphere interaction is also responsible of heating the corona. The reprocessing of the beam leads to a turbulent atmospheric layer where outward moving double layers are being excited. These uprising particle-acceleration sites are similar to earthly auroras, and are a possible new source of non-thermal X-ray radiation from neutron stars. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Wed Feb 6 21:16:01 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Wed, 6 Feb 2019 20:16:01 +0000 Subject: [Okc-wp4] EO Meeting on Feb 7 (note the slight change in schedule) Message-ID: <17d6ce7947ee4d95a29051e38bc72358@astro.su.se> Dear all, our first EO meeting of 2019 will be this Thursday Feb 7 from 13:15 to 14:00 (KTH meeting room on the 5th floor). Joonas Nättilä will give the following talk: Title: Magnetically-dominated collisionless plasma flows in neutron star atmospheres Abstract: I will discuss collisionless plasma instabilities operating on magnetically-dominated flows in neutron star atmospheres. We define a criteria for out-of-resonance two-stream instability to be operational in the stratified atmosphere. Our theoretical findings are then confirmed with high-resolution, first-principles relativistic Vlasov-Maxwell simulations. This allows us to study the subsequent non-linear turbulent evolution of the system. We find a new plasma mechanism that reprocesses the incoming mildly-relativistic beams: The incoming beams are slowed down, heated up, but not brought to full halt either. Ultra-relativistic beams are still capable of penetrating into the star unaffected. This implies that diluted free-falling accretion flows into neutron stars are always reprocessed in the uppermost layers of the star's atmosphere before entering the particle-collision-dominated layers below. This beam-atmosphere interaction is also responsible of heating the corona. The reprocessing of the beam leads to a turbulent atmospheric layer where outward moving double layers are being excited. These uprising particle-acceleration sites are similar to earthly auroras, and are a possible new source of non-thermal X-ray radiation from neutron stars. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Tue Feb 19 14:33:39 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Tue, 19 Feb 2019 13:33:39 +0000 Subject: [Okc-wp4] EO Meeting on Fev 21 Message-ID: <49f085c782de4f838d2e3a2694a56ac5@astro.su.se> Dear all, our next EO meeting will take place this Thursday Feb 21 at 13:00 in the KTH meeting room on the 5th floor. Filip Samuelsson will present the following talk Title: The problematic connection between gamma-ray bursts (GRBs) and ultra-high energy cosmic rays (UHECR) Abstract: The acceleration site for UHECR is still an open question despite extended research. We consider the prompt phase of GRBs as a possible origin for these high energy particles. Under the likely assumption that electrons are also accelerated at the UHECR acceleration site, synchrotron emission from these co-accelerated electrons is inevitable. We characterize this synchrotron emission and compare it to observed GRB spectra and find that for standard parameters, the synchrotron flux from these electrons would be much too luminous. This result challenges both high- and low-luminosity GRBs as accelerators of UHECR. --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From kunal.deoskar at fysik.su.se Tue Feb 19 14:35:05 2019 From: kunal.deoskar at fysik.su.se (Kunal Deoskar) Date: Tue, 19 Feb 2019 13:35:05 +0000 Subject: [Okc-wp4] EO Meeting on Fev 21 Message-ID: our next EO meeting will take place this Thursday Feb 21 at 13:00 in the KTH meeting room on the 5th floor. -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: text/calendar Size: 1728 bytes Desc: not available URL: From kunal.deoskar at fysik.su.se Tue Feb 19 14:38:21 2019 From: kunal.deoskar at fysik.su.se (Kunal Deoskar) Date: Tue, 19 Feb 2019 13:38:21 +0000 Subject: [Okc-wp4] Canceled: EO Meeting on Fev 21 Message-ID: <2a59f29803fb416d80be5dd99c65b033@fysik.su.se> -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: text/calendar Size: 1985 bytes Desc: not available URL: From kunal.deoskar at fysik.su.se Tue Feb 19 14:47:25 2019 From: kunal.deoskar at fysik.su.se (Kunal Deoskar) Date: Tue, 19 Feb 2019 13:47:25 +0000 Subject: [Okc-wp4] EO Meeting on Fev 21 In-Reply-To: <2a59f29803fb416d80be5dd99c65b033@fysik.su.se> References: <2a59f29803fb416d80be5dd99c65b033@fysik.su.se> Message-ID: Hi, Sorry regarding the previous emails, I had accidentally clicked on 'schedule an event' for the EO meeting so had to cancel my copy of it. See you on Thursday. Cheers, Kunal ________________________________ From: Kunal Deoskar Sent: Tuesday, February 19, 2019 2:38 PM To: Andre Schneider; Okc-wp4 at fysik.su.se Cc: Francesco Taddia; Joonas Nättilä; Filip Samuelsson; Francesca Capel Subject: Canceled: [Okc-wp4] EO Meeting on Fev 21 When: Thursday, February 21, 2019 1:00 PM-1:30 PM. Where: -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Thu Feb 21 12:19:16 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 21 Feb 2019 11:19:16 +0000 Subject: [Okc-wp4] EO Meeting on Fev 21 In-Reply-To: <49f085c782de4f838d2e3a2694a56ac5@astro.su.se> References: <49f085c782de4f838d2e3a2694a56ac5@astro.su.se> Message-ID: <50c29baf754c481c94b1f24d0101a65f@astro.su.se> This is a reminder of our EO meeting today at 13:00! See you there! Dear all, our next EO meeting will take place this Thursday Feb 21 at 13:00 in the KTH meeting room on the 5th floor. Filip Samuelsson will present the following talk Title: The problematic connection between gamma-ray bursts (GRBs) and ultra-high energy cosmic rays (UHECR) Abstract: The acceleration site for UHECR is still an open question despite extended research. We consider the prompt phase of GRBs as a possible origin for these high energy particles. Under the likely assumption that electrons are also accelerated at the UHECR acceleration site, synchrotron emission from these co-accelerated electrons is inevitable. We characterize this synchrotron emission and compare it to observed GRB spectra and find that for standard parameters, the synchrotron flux from these electrons would be much too luminous. This result challenges both high- and low-luminosity GRBs as accelerators of UHECR. --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Mon Feb 25 14:25:25 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Mon, 25 Feb 2019 13:25:25 +0000 Subject: [Okc-wp4] EO Meeting on Fev 28 Message-ID: Dear colleagues, our next EO meeting will take place this Thursday Feb 28 at 13:15 in the KTH meeting room on the 5th floor. Dr Dan Perley visiting from LJMU will present us the following talk Multiwavelength Observations of the Extreme Transient AT2018cow The bright, luminous, and fast multiwavelength transient AT2018cow displayed unprecedented behavior at almost every waveband: a fast-evolving UV/optical counterpart that maintains an extremely hot photospheric temperature over its entire evolution, an erratically-fluctuating luminous X-ray counterpart, and a heavily self-absorbed radio/submillimeter counterpart. We present a comprehensive set of photometric and spectroscopic observations of this transient from groundbased observatories spanning four continents and from space, including multiwavelength observations from Swift, NuSTAR, Astrosat, SMA, and ALMA. We consider both supernova and intermediate-mass black hole tidal disruption event interpretations for its origin, although no simple theoretical model can explain the full set of observations. Transients similar to AT2018cow are probably not rare in the universe: we are on the alert for more such objects within ZTF, and anticipate that they will be detected in large numbers by LSST in the coming decade. --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From stephan.rosswog at astro.su.se Thu Feb 28 12:18:25 2019 From: stephan.rosswog at astro.su.se (Stephan Rosswog) Date: Thu, 28 Feb 2019 11:18:25 +0000 Subject: [Okc-wp4] EO Meeting on Fev 28 In-Reply-To: References: Message-ID: KIND REMINDER. On 25 Feb 2019, at 14:25, Andre Schneider > wrote: Dear colleagues, our next EO meeting will take place this Thursday Feb 28 at 13:15 in the KTH meeting room on the 5th floor. Dr Dan Perley visiting from LJMU will present us the following talk Multiwavelength Observations of the Extreme Transient AT2018cow The bright, luminous, and fast multiwavelength transient AT2018cow displayed unprecedented behavior at almost every waveband: a fast-evolving UV/optical counterpart that maintains an extremely hot photospheric temperature over its entire evolution, an erratically-fluctuating luminous X-ray counterpart, and a heavily self-absorbed radio/submillimeter counterpart. We present a comprehensive set of photometric and spectroscopic observations of this transient from groundbased observatories spanning four continents and from space, including multiwavelength observations from Swift, NuSTAR, Astrosat, SMA, and ALMA. We consider both supernova and intermediate-mass black hole tidal disruption event interpretations for its origin, although no simple theoretical model can explain the full set of observations. Transients similar to AT2018cow are probably not rare in the universe: we are on the alert for more such objects within ZTF, and anticipate that they will be detected in large numbers by LSST in the coming decade. --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University ------------------------------------------------- okc-wp4 at albanova.se mailing list ---------------------------------------------- Prof. Dr. Stephan Rosswog Computational High-Energy Astrophysics The Oskar Klein Centre for Cosmoparticle Physics Department of Astronomy, Stockholm University AlbaNova, Roslagstullbacken 21 SE-10691 Stockholm, Sweden Email: stephan.rosswog at astro.su.se Tel.: +46 (0)8 5537 8529 URL: http://compact-merger.astro.su.se/ -------------- next part -------------- An HTML attachment was scrubbed... URL: From ariel at fysik.su.se Thu Mar 21 10:03:42 2019 From: ariel at fysik.su.se (Ariel Goobar) Date: Thu, 21 Mar 2019 09:03:42 +0000 Subject: [Okc-wp4] Pre-defence seminar by Semeli Papadogiannakis; March 22 at 13:00 hs in A5:1041 Message-ID: Welcome to Semeli’s pre-defence seminar where she will tell us about her thesis project: “Properties of Type Ia Supernovae from the (intermediate) Palomar Transient Factory” Friday, March 22 at 13:00 hs in room A5:1041 Ariel ___________________________________________________________________ Professor Ariel Goobar The Oskar Klein Centre for Cosmoparticle Physics Department of Physics, Stockholm University AlbaNova University Center, SE-106 91 Stockholm, SWEDEN tel:+46 8 55378659 fax:+46 8 55378601 web: www.fysik.su.se/~ariel -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Mon Mar 25 13:04:51 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Mon, 25 Mar 2019 12:04:51 +0000 Subject: [Okc-wp4] EO meeting Thu Mar 28 @ 13:15 KTH meeting room Message-ID: Dear colleagues, our next EO meeting will take place this Thursday Mar 28 at 13:15 in the KTH meeting room on the 5th floor. Mattia Bulla will present us the following talk Characterizing the first few hours: young Type Ia supernovae from the Zwicky Transient Facility I will present preliminary results of an ongoing analysis to characterize Type Ia supernovae in the first few days after explosion. In particular, I will focus on a sample of 27 young Type Ia supernovae discovered by the Zwicky Transient Facility in 2018 and show how this can place constraints on the Type Ia supernova progenitor(s) and/or explosion mechanism(s)." See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Thu Mar 28 11:32:37 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 28 Mar 2019 10:32:37 +0000 Subject: [Okc-wp4] EO meeting Thu Mar 28 @ 13:15 KTH meeting room In-Reply-To: References: Message-ID: <0780155380b247abb9a6ac8221ae657e@astro.su.se> Reminder of the EO meeting today. --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Andre Schneider Sent: Monday, March 25, 2019 1:04:51 PM To: Okc-wp4 at fysik.su.se Subject: [Okc-wp4] EO meeting Thu Mar 28 @ 13:15 KTH meeting room Dear colleagues, our next EO meeting will take place this Thursday Mar 28 at 13:15 in the KTH meeting room on the 5th floor. Mattia Bulla will present us the following talk Characterizing the first few hours: young Type Ia supernovae from the Zwicky Transient Facility I will present preliminary results of an ongoing analysis to characterize Type Ia supernovae in the first few days after explosion. In particular, I will focus on a sample of 27 young Type Ia supernovae discovered by the Zwicky Transient Facility in 2018 and show how this can place constraints on the Type Ia supernova progenitor(s) and/or explosion mechanism(s)." See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Thu Mar 28 12:02:17 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 28 Mar 2019 11:02:17 +0000 Subject: [Okc-wp4] Fri Mar 29 @ 10:00 KTH meeting room Message-ID: Dear colleagues, this talk tomorrow should be of interest to many of us in the EO Working Group. On Fri Mar 29, @ 10:00 in the KTH meeting room Dan Kocevski from NASA/MSFC will be presenting the following talk Title: Understanding the electromagnetic emission from the first gravitational wave detection of merging neutron stars Abstract: The joint detection of merging neutron stars in gravitational waves (GWs) by LIGO/Virgo and in gamma rays by the Fermi Gamma-ray Burst Monitor (GBM) provided the first direct evidence for the long suspected connection between short gamma-ray bursts and the merger of two compact objects. The complementary information encoded in the electromagnetic signal showed that such observations can provide essential astrophysical context to gravitational wave detections. Despite the wealth of information that was gained by the multi-wavelength observations of this event and the associated kilonova, many questions regarding the nature of the high-energy emission still remain and have become a source of vigorous debate within the community. I will discuss these open questions and present an overview of the theories that have been put forth to explain the high-energy observations. I will also propose observational signatures that could help better discriminate between these competing theories in future detections. --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From ariel at fysik.su.se Thu Mar 28 14:17:53 2019 From: ariel at fysik.su.se (Ariel Goobar) Date: Thu, 28 Mar 2019 13:17:53 +0000 Subject: [Okc-wp4] =?utf-8?q?Master_Thesis_defense=3A_Karl_Johanstr=C3=B6m?= =?utf-8?q?mer=2C_Monday_April_1=2C_10=3A00_in_FA31?= Message-ID: <59A78CAF-88F2-4A9D-93BF-C3B56678669A@fysik.su.se> Welcome to Karl Johanströmmer’s Master's Thesis presentation on Monday at 10:00 in FA31 on the subject of “Dust in the Intergalactic medium and Type Ia supernovae” Ariel ___________________________________________________________________ Professor Ariel Goobar The Oskar Klein Centre for Cosmoparticle Physics Department of Physics, Stockholm University AlbaNova University Center, SE-106 91 Stockholm, SWEDEN tel:+46 8 55378659 fax:+46 8 55378601 web: www.fysik.su.se/~ariel -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Mon Apr 1 12:22:52 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Mon, 1 Apr 2019 10:22:52 +0000 Subject: [Okc-wp4] EO meeting Thu Apr 4 @ 13:15 KTH meeting room Message-ID: <09eee12d849f47d7ac940b3d1335672f@astro.su.se> Dear colleagues, our next EO meeting will take place this Thursday Apr 4 at 13:15 in the KTH meeting room on the 5th floor. Sanjay Reddy, who is visiting from the University of Washington, will present us the following talk: Title: The Dark Side of Neutron Stars Abstract: Neutron stars provide unique opportunities to discover or constrain dark matter. I will discuss a few recent proposals and their implications. Very weakly interacting particles be produced or accreted onto neutron stars, the challenge is to identify observable signatures. I will discuss how gravitational waves, neutrinos and x-rays from neutron stars can provide new ways to constrain compact dark objects, and some types of particle dark matter. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Thu Apr 4 09:59:44 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 4 Apr 2019 07:59:44 +0000 Subject: [Okc-wp4] EO meeting Thu Apr 4 @ 13:15 KTH meeting room In-Reply-To: <09eee12d849f47d7ac940b3d1335672f@astro.su.se> References: <09eee12d849f47d7ac940b3d1335672f@astro.su.se> Message-ID: REMINDER of Sanjay Reddy's EO meeting talk today. Dear colleagues, our next EO meeting will take place this Thursday Apr 4 at 13:15 in the KTH meeting room on the 5th floor. Sanjay Reddy, who is visiting from the University of Washington, will present us the following talk: Title: The Dark Side of Neutron Stars Abstract: Neutron stars provide unique opportunities to discover or constrain dark matter. I will discuss a few recent proposals and their implications. Very weakly interacting particles be produced or accreted onto neutron stars, the challenge is to identify observable signatures. I will discuss how gravitational waves, neutrinos and x-rays from neutron stars can provide new ways to constrain compact dark objects, and some types of particle dark matter. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Sun Apr 28 21:28:51 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Sun, 28 Apr 2019 19:28:51 +0000 Subject: [Okc-wp4] EO meeting Thu May 2 @ 13:15 KTH meeting room Message-ID: Dear colleagues, our next EO meeting will take place this Thursday May 2 at 13:15 in the KTH meeting room on the 5th floor. Alexandra Veledina, from NORDITA, will present us the following talk: Title: The mystery of transitional millisecond pulsars Abstract: Radio millisecond pulsars are fast-rotating neutron stars which are believed to have been spun up by the proceeding accretion processes. This formation scenario assumes there are periods of time when the pulsar is actively accreting. It has been confirmed by the discovery of the so-called transitional millisecond pulsars, the systems which were detected both as radio pulsars and, at some other time, as accreting millisecond X-ray pulsars. These sources also provide a unique dataset to study low-level accretion and demonstrate rich variety of observational properties. I will give an overview of the recent observations of such systems and describe a physical model for the observed multiwavelength behaviour. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Thu May 2 11:48:07 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 2 May 2019 09:48:07 +0000 Subject: [Okc-wp4] EO meeting Thu May 2 @ 13:15 KTH meeting room In-Reply-To: References: Message-ID: Reminder of the EO Meeting at 13:15 today! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Andre Schneider Sent: Sunday, April 28, 2019 9:28 PM To: Okc-wp4 at fysik.su.se Subject: [Okc-wp4] EO meeting Thu May 2 @ 13:15 KTH meeting room Dear colleagues, our next EO meeting will take place this Thursday May 2 at 13:15 in the KTH meeting room on the 5th floor. Alexandra Veledina, from NORDITA, will present us the following talk: Title: The mystery of transitional millisecond pulsars Abstract: Radio millisecond pulsars are fast-rotating neutron stars which are believed to have been spun up by the proceeding accretion processes. This formation scenario assumes there are periods of time when the pulsar is actively accreting. It has been confirmed by the discovery of the so-called transitional millisecond pulsars, the systems which were detected both as radio pulsars and, at some other time, as accreting millisecond X-ray pulsars. These sources also provide a unique dataset to study low-level accretion and demonstrate rich variety of observational properties. I will give an overview of the recent observations of such systems and describe a physical model for the observed multiwavelength behaviour. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Mon May 13 14:04:46 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Mon, 13 May 2019 12:04:46 +0000 Subject: [Okc-wp4] EO meeting Thu May 16 @ 13:15 KTH meeting room Message-ID: Dear colleagues, our next EO meeting will take place this Thursday May 16 at 13:15 in the KTH meeting room on the 5th floor. Danny Goldstein from Caltech will present us the following talk Title: Time-Domain Approaches to Investigating the Tension in H0 Abstract: State-of-the-art local and primordial measurements of the Hubble constant (H0) are currently in tension at the 4.4 sigma level. New physics and systematic errors have been invoked as potential explanations. I will discuss two new, independent techniques for measuring H0 from time-domain astronomy that can help distinguish between these and other scenarios. The first is to use time delays from strongly gravitationally lensed supernovae to constrain H0 geometrically. The second is to construct a distance-redshift relation using electromagnetic counterparts to gravitational wave events. I will describe experimental efforts that are currently underway to carry out both of these measurements, namely the Zwicky Transient Facility lensed supernova search and the Dark Energy Camera neutron star merger follow-up program. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Thu May 16 11:37:19 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 16 May 2019 09:37:19 +0000 Subject: [Okc-wp4] EO meeting Thu May 16 @ 13:15 KTH meeting room In-Reply-To: References: Message-ID: Reminder of the EO meeting today. --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Andre Schneider Sent: Monday, May 13, 2019 2:04:46 PM To: Okc-wp4 at fysik.su.se Subject: [Okc-wp4] EO meeting Thu May 16 @ 13:15 KTH meeting room Dear colleagues, our next EO meeting will take place this Thursday May 16 at 13:15 in the KTH meeting room on the 5th floor. Danny Goldstein from Caltech will present us the following talk Title: Time-Domain Approaches to Investigating the Tension in H0 Abstract: State-of-the-art local and primordial measurements of the Hubble constant (H0) are currently in tension at the 4.4 sigma level. New physics and systematic errors have been invoked as potential explanations. I will discuss two new, independent techniques for measuring H0 from time-domain astronomy that can help distinguish between these and other scenarios. The first is to use time delays from strongly gravitationally lensed supernovae to constrain H0 geometrically. The second is to construct a distance-redshift relation using electromagnetic counterparts to gravitational wave events. I will describe experimental efforts that are currently underway to carry out both of these measurements, namely the Zwicky Transient Facility lensed supernova search and the Dark Energy Camera neutron star merger follow-up program. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Mon May 20 15:10:08 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Mon, 20 May 2019 13:10:08 +0000 Subject: [Okc-wp4] EO meeting Thu May 23 @ 13:15 KTH meeting room Message-ID: Dear colleagues, our next EO meeting will take place this Thursday May 16 at 13:15 in the KTH meeting room on the 5th floor. This week Eddie Baron from University of Oklahoma will present the following talk: Title: SNe Ia Progenitors. Wait. What? Abstract: I present a brief history of the theoretical understanding of the progenitor/explosion scenario for SNe Ia. I describe the currently viable models and suggest some possible ways to make progress distinguishing among the viable scenarios. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Mon May 20 15:11:56 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Mon, 20 May 2019 13:11:56 +0000 Subject: [Okc-wp4] EO meeting Thu May 23 @ 13:15 KTH meeting room In-Reply-To: References: Message-ID: I'm sorry, below is the announcement with the correct that on the body of the e-mail. Dear colleagues, our next EO meeting will take place this Thursday May 23 at 13:15 in the KTH meeting room on the 5th floor. This week Eddie Baron from University of Oklahoma will present the following talk: Title: SNe Ia Progenitors. Wait. What? Abstract: I present a brief history of the theoretical understanding of the progenitor/explosion scenario for SNe Ia. I describe the currently viable models and suggest some possible ways to make progress distinguishing among the viable scenarios. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Andre Schneider Sent: Monday, May 20, 2019 3:10:08 PM To: Okc-wp4 at fysik.su.se Subject: [Okc-wp4] EO meeting Thu May 23 @ 13:15 KTH meeting room Dear colleagues, our next EO meeting will take place this Thursday May 16 at 13:15 in the KTH meeting room on the 5th floor. This week Eddie Baron from University of Oklahoma will present the following talk: Title: SNe Ia Progenitors. Wait. What? Abstract: I present a brief history of the theoretical understanding of the progenitor/explosion scenario for SNe Ia. I describe the currently viable models and suggest some possible ways to make progress distinguishing among the viable scenarios. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Thu May 23 11:25:23 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 23 May 2019 09:25:23 +0000 Subject: [Okc-wp4] EO meeting Thu May 23 @ 13:15 KTH meeting room Message-ID: Reminder of the EO meeting early this afternoon with Eddie Baron from University of Oklahoma On May 20, 2019 15:12, Andre Schneider wrote: I'm sorry, below is the announcement with the correct that on the body of the e-mail. Dear colleagues, our next EO meeting will take place this Thursday May 23 at 13:15 in the KTH meeting room on the 5th floor. This week Eddie Baron from University of Oklahoma will present the following talk: Title: SNe Ia Progenitors. Wait. What? Abstract: I present a brief history of the theoretical understanding of the progenitor/explosion scenario for SNe Ia. I describe the currently viable models and suggest some possible ways to make progress distinguishing among the viable scenarios. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Andre Schneider Sent: Monday, May 20, 2019 3:10:08 PM To: Okc-wp4 at fysik.su.se Subject: [Okc-wp4] EO meeting Thu May 23 @ 13:15 KTH meeting room Dear colleagues, our next EO meeting will take place this Thursday May 16 at 13:15 in the KTH meeting room on the 5th floor. This week Eddie Baron from University of Oklahoma will present the following talk: Title: SNe Ia Progenitors. Wait. What? Abstract: I present a brief history of the theoretical understanding of the progenitor/explosion scenario for SNe Ia. I describe the currently viable models and suggest some possible ways to make progress distinguishing among the viable scenarios. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Mon Sep 23 11:34:38 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Mon, 23 Sep 2019 09:34:38 +0000 Subject: [Okc-wp4] EO meeting Thu Sep 26 @ 13:15 KTH meeting room Message-ID: <7a475becf347470e9f95c7695f0fe175@astro.su.se> Dear colleagues, our next EO meeting will take place this Thursday Sep 26 at 13:15 in the KTH meeting room on the 5th floor. There will be two talks. a) Jens Mahlmann will present Simulating Poynting dominated energy flows around magnetars and black holes We employ our implementation of General Relativistic force- free electrodynamics within the framework of the Einstein Toolkit in order to explore progenitor magnetospheres of high-luminosity transient events. Presenting recent results from simulations of twisted magnetospheres of highly magnetized neutron stars (magnetars) we demonstrate the instability of certain high-energy solutions to the Grad- Shafranov equation, potentially liberating a significant amount of energy to the magnetosphere and onto the magnetar crust. Further, we probe the energy extraction from rapidly spinning black holes via the Blandford/Znajek process] in progenitor models without a large scale magnetic flux by employing an accretion model for a system of magnetic loops on a dynamically evolving spacetime. b) Vivek Chaurasia will present Neutron Stars In Numerical Relativity In this talk I will briefly present the updates from my doctoral thesis work on simulating highly eccentric neutron star binaries using state-of-the-art BAM code which is a finite difference code. Additionally, I will also present some results from a relatively new methodology which is based on spectral methods, namely the Discontinuous Galerkin methods, in solving the general relativistic hydrodynamics equations. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From aurore.betranhandy at astro.su.se Wed Sep 25 16:07:42 2019 From: aurore.betranhandy at astro.su.se (Aurore Betranhandy) Date: Wed, 25 Sep 2019 14:07:42 +0000 Subject: [Okc-wp4] EO meeting Thu Sep 26 @ 13:15 KTH meeting room Message-ID: <3567167093e2449a92cf4f881acc12fb@astro.su.se> Sep 26 at 13:15 in the KTH meeting room on the 5th floor. -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: text/calendar Size: 1717 bytes Desc: not available URL: From aurore.betranhandy at astro.su.se Wed Sep 25 16:37:46 2019 From: aurore.betranhandy at astro.su.se (Aurore Betranhandy) Date: Wed, 25 Sep 2019 14:37:46 +0000 Subject: [Okc-wp4] Canceled: EO meeting Thu Sep 26 @ 13:15 KTH meeting room Message-ID: -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: text/calendar Size: 2023 bytes Desc: not available URL: From aurore.betranhandy at astro.su.se Wed Sep 25 16:41:44 2019 From: aurore.betranhandy at astro.su.se (Aurore Betranhandy) Date: Wed, 25 Sep 2019 14:41:44 +0000 Subject: [Okc-wp4] EO meeting Thu Sep 26 @ 13:15 KTH meeting room In-Reply-To: <3567167093e2449a92cf4f881acc12fb@astro.su.se> References: <3567167093e2449a92cf4f881acc12fb@astro.su.se> Message-ID: <8d15720970264a9cbc1ef2e5bfbb6b3c@astro.su.se> Sorry for the bizarre event planning, I did a wrong calendar manipulation. Aurore ________________________________ From: Aurore Betranhandy Sent: 25 September 2019 16:07:42 To: Andre Schneider; Okc-wp4 at fysik.su.se Subject: [Okc-wp4] EO meeting Thu Sep 26 @ 13:15 KTH meeting room When: 26 September 2019 13:15-13:45. Where: Sep 26 at 13:15 in the KTH meeting room on the 5th floor. -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Thu Sep 26 10:54:47 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 26 Sep 2019 08:54:47 +0000 Subject: [Okc-wp4] EO meeting Thu Sep 26 @ 13:15 KTH meeting room In-Reply-To: <7a475becf347470e9f95c7695f0fe175@astro.su.se> References: <7a475becf347470e9f95c7695f0fe175@astro.su.se> Message-ID: <64fe47e016294dca8b074a9de99ee587@astro.su.se> Reminder of out first EO meeting of this fall this afternoon. --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Andre Schneider Sent: Monday, September 23, 2019 11:34:38 AM To: Okc-wp4 at fysik.su.se Subject: [Okc-wp4] EO meeting Thu Sep 26 @ 13:15 KTH meeting room Dear colleagues, our next EO meeting will take place this Thursday Sep 26 at 13:15 in the KTH meeting room on the 5th floor. There will be two talks. a) Jens Mahlmann will present Simulating Poynting dominated energy flows around magnetars and black holes We employ our implementation of General Relativistic force- free electrodynamics within the framework of the Einstein Toolkit in order to explore progenitor magnetospheres of high-luminosity transient events. Presenting recent results from simulations of twisted magnetospheres of highly magnetized neutron stars (magnetars) we demonstrate the instability of certain high-energy solutions to the Grad- Shafranov equation, potentially liberating a significant amount of energy to the magnetosphere and onto the magnetar crust. Further, we probe the energy extraction from rapidly spinning black holes via the Blandford/Znajek process] in progenitor models without a large scale magnetic flux by employing an accretion model for a system of magnetic loops on a dynamically evolving spacetime. b) Vivek Chaurasia will present Neutron Stars In Numerical Relativity In this talk I will briefly present the updates from my doctoral thesis work on simulating highly eccentric neutron star binaries using state-of-the-art BAM code which is a finite difference code. Additionally, I will also present some results from a relatively new methodology which is based on spectral methods, namely the Discontinuous Galerkin methods, in solving the general relativistic hydrodynamics equations. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Tue Oct 8 19:21:10 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Tue, 8 Oct 2019 17:21:10 +0000 Subject: [Okc-wp4] EO meeting Thu Oct 10 @ 13:15 KTH meeting room Message-ID: Dear colleagues, our next EO meeting will take place this Thursday Oct 10 at 13:15 in the KTH meeting room on the 5th floor. Filip Samuelsson will present the following talk: Title: Radiation mediated shock in gamma-ray bursts. Abstract: Five decades since the first discovery of a gamma-ray burst (GRB), the prompt emission mechanism remains an open question. One promising candidate is that the high-energy emission originates from the photosphere, where the ejecta transitions from opaque to optically thin. Hydrodynamical simulations of GRB jets show that shocks are likely to form below the photosphere and due to the high radiation pressure in the optically thick region, these shocks will be radiation mediated. In this talk, I will discuss how such shocks alters the shape of the spectrum released at the photosphere. Furthermore, I present a model that we have developed, which hopefully can explain a wide variety of GRB prompt emission spectra. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Thu Oct 10 10:18:08 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 10 Oct 2019 08:18:08 +0000 Subject: [Okc-wp4] EO meeting Thu Oct 10 @ 13:15 KTH meeting room In-Reply-To: References: Message-ID: <1ddeb53492ed46f68a7e80ca5bd34184@astro.su.se> Reminder of the Extreme Objects meeting this afternoon! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Andre Schneider Sent: Tuesday, October 8, 2019 7:21:10 PM To: Okc-wp4 at fysik.su.se Subject: [Okc-wp4] EO meeting Thu Oct 10 @ 13:15 KTH meeting room Dear colleagues, our next EO meeting will take place this Thursday Oct 10 at 13:15 in the KTH meeting room on the 5th floor. Filip Samuelsson will present the following talk: Title: Radiation mediated shock in gamma-ray bursts. Abstract: Five decades since the first discovery of a gamma-ray burst (GRB), the prompt emission mechanism remains an open question. One promising candidate is that the high-energy emission originates from the photosphere, where the ejecta transitions from opaque to optically thin. Hydrodynamical simulations of GRB jets show that shocks are likely to form below the photosphere and due to the high radiation pressure in the optically thick region, these shocks will be radiation mediated. In this talk, I will discuss how such shocks alters the shape of the spectrum released at the photosphere. Furthermore, I present a model that we have developed, which hopefully can explain a wide variety of GRB prompt emission spectra. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Mon Oct 28 09:36:46 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Mon, 28 Oct 2019 08:36:46 +0000 Subject: [Okc-wp4] EO meeting Thu Oct 31 @ 13:15 KTH meeting room Message-ID: <54994d6135334ea590f0e84058ff06fb@astro.su.se> Dear colleagues, our next EO meeting will take place this Thursday Oct 31 at 13:15 in the KTH meeting room on the 5th floor. Suhail Dhawan will present the following talk. Title: H0 with explosive transients Abstract: The Hubble constant sets the absolute distance scale of the universe. Recent, precision measurements of the Hubble constant with the local distance ladder are in tension with the value inferred from the cosmic microwave background, assuming the standard cosmological model. This tension could suggest possible evidence for non-standard cosmologies, e.g. additional neutrino species or phantom dark energy. However, it could also be due to something more mundane like unknown sources of systematic errors. Hence, we need to test for sources of systematics in the distance ladder, but also measure H0 from completely independent sources. In this talk, I show results from our recent work on testing for systematic uncertainties from the Type Ia supernova wrung of the distance ladder. Strongly lensed transients (e.g. supernovae, quasars) have long been proposed as a method to measure the Hubble constant. I will talk about our recent work on measuring time delays, lensing magnification and extinction properties of the first resolved, strongly lensed Type Ia supernova. Another promising method to measure H0 is using gravitational wave (GW) standard sirens (GW equivalent of standard candles). Here, I will summarise a recent study on using the electromagnetic counterpart of GW standard sirens and implications for H0 from the first GW source with an identified EM counterpart, GW170817. In the end, I will review some possibilities of non-standard cosmologies that could resolve the tension. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Thu Oct 31 10:19:48 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 31 Oct 2019 09:19:48 +0000 Subject: [Okc-wp4] EO meeting Thu Oct 31 @ 13:15 KTH meeting room In-Reply-To: <54994d6135334ea590f0e84058ff06fb@astro.su.se> References: <54994d6135334ea590f0e84058ff06fb@astro.su.se> Message-ID: <4aee3bf967f444bd98261be88dd5595c@astro.su.se> Reminder of the EO meeting this afternoon. --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Andre Schneider Sent: Monday, October 28, 2019 9:36:46 AM To: okc-wp4 at fysik.su.se; people at nordita.org Subject: [Okc-wp4] EO meeting Thu Oct 31 @ 13:15 KTH meeting room Dear colleagues, our next EO meeting will take place this Thursday Oct 31 at 13:15 in the KTH meeting room on the 5th floor. Suhail Dhawan will present the following talk. Title: H0 with explosive transients Abstract: The Hubble constant sets the absolute distance scale of the universe. Recent, precision measurements of the Hubble constant with the local distance ladder are in tension with the value inferred from the cosmic microwave background, assuming the standard cosmological model. This tension could suggest possible evidence for non-standard cosmologies, e.g. additional neutrino species or phantom dark energy. However, it could also be due to something more mundane like unknown sources of systematic errors. Hence, we need to test for sources of systematics in the distance ladder, but also measure H0 from completely independent sources. In this talk, I show results from our recent work on testing for systematic uncertainties from the Type Ia supernova wrung of the distance ladder. Strongly lensed transients (e.g. supernovae, quasars) have long been proposed as a method to measure the Hubble constant. I will talk about our recent work on measuring time delays, lensing magnification and extinction properties of the first resolved, strongly lensed Type Ia supernova. Another promising method to measure H0 is using gravitational wave (GW) standard sirens (GW equivalent of standard candles). Here, I will summarise a recent study on using the electromagnetic counterpart of GW standard sirens and implications for H0 from the first GW source with an identified EM counterpart, GW170817. In the end, I will review some possibilities of non-standard cosmologies that could resolve the tension. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Mon Nov 4 12:54:21 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Mon, 4 Nov 2019 11:54:21 +0000 Subject: [Okc-wp4] EO meeting Thu Nov 07 @ 13:15 KTH meeting room Message-ID: <883344fb75b847b4982d0695211a8e8e@astro.su.se> Dear colleagues, our next EO meeting will take place this Thursday, Nov 07 at 13:15. The meeting will take place at the KTH meeting room on the 5th floor of the AlbaNova University Centre. Speaker: Davide Gizze Title: Modeling neutrino transport in binary neutron star mergers Abstract: Neutrinos, copiously produced in the hot environment of merging neutron stars, play an important role in the dynamics of a merger. In particular, neutrino absorption drives mass ejection, the so called neutrino-driven winds. Moreover, neutrinos reprocess the electron fraction in the ejecta from a neutron star merger, with consequent impact on the nucleosynthesis of the r-process nuclei. The electron fraction in neutrino-driven winds is such that only a weak r-process occurs. The detection of a bright blue kilonova from GW170817 was a clear signature of the presence of weak interactions in mergers. Modeling neutrino-driven winds is therefore crucial for future kilonovae detections. In this talk, I will first introduce the challenging topic of neutrino transport. I will then focus on an approximate neutrino transport approach called Advanced Spectral Leakage (ASL). The ASL was initially designed for neutrino transport in the context of core-collapse supernovae simulations. I will describe how we extended the original implementation of the ASL to model neutrino-driven winds in neutron star merger simulations, together with numerical tests performed over snapshots. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From quentin.pognan at astro.su.se Mon Nov 4 13:26:27 2019 From: quentin.pognan at astro.su.se (Quentin Pognan) Date: Mon, 4 Nov 2019 12:26:27 +0000 Subject: [Okc-wp4] our next EO meeting Message-ID: <10b5029434fd4205881c921daf489199@astro.su.se> our next EO meeting will take place this Thursday, Nov 07 at 13:15. -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: text/calendar Size: 1816 bytes Desc: not available URL: From andre.schneider at astro.su.se Thu Nov 7 10:45:28 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 7 Nov 2019 09:45:28 +0000 Subject: [Okc-wp4] EO meeting Thu Nov 07 @ 13:15 KTH meeting room In-Reply-To: <883344fb75b847b4982d0695211a8e8e@astro.su.se> References: <883344fb75b847b4982d0695211a8e8e@astro.su.se> Message-ID: Reminder of our EO meeting this afternoon! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Andre Schneider Sent: Monday, November 4, 2019 12:54:21 PM To: Okc-wp4 at fysik.su.se; people at nordita.org Subject: [Okc-wp4] EO meeting Thu Nov 07 @ 13:15 KTH meeting room Dear colleagues, our next EO meeting will take place this Thursday, Nov 07 at 13:15. The meeting will take place at the KTH meeting room on the 5th floor of the AlbaNova University Centre. Speaker: Davide Gizze Title: Modeling neutrino transport in binary neutron star mergers Abstract: Neutrinos, copiously produced in the hot environment of merging neutron stars, play an important role in the dynamics of a merger. In particular, neutrino absorption drives mass ejection, the so called neutrino-driven winds. Moreover, neutrinos reprocess the electron fraction in the ejecta from a neutron star merger, with consequent impact on the nucleosynthesis of the r-process nuclei. The electron fraction in neutrino-driven winds is such that only a weak r-process occurs. The detection of a bright blue kilonova from GW170817 was a clear signature of the presence of weak interactions in mergers. Modeling neutrino-driven winds is therefore crucial for future kilonovae detections. In this talk, I will first introduce the challenging topic of neutrino transport. I will then focus on an approximate neutrino transport approach called Advanced Spectral Leakage (ASL). The ASL was initially designed for neutrino transport in the context of core-collapse supernovae simulations. I will describe how we extended the original implementation of the ASL to model neutrino-driven winds in neutron star merger simulations, together with numerical tests performed over snapshots. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Mon Nov 18 14:18:14 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Mon, 18 Nov 2019 13:18:14 +0000 Subject: [Okc-wp4] EO meeting Thu Nov 21 @ 13:15 KTH meeting room Message-ID: Dear colleagues, the next EO meeting will take place this Thursday Nov 21 at 13:15 in the KTH meeting room on the 5th floor of the AlbaNova University Centre. Speaker: Giovanni Camelio Title: Rotating neutron stars with non-barotropic thermal profile Abstract: Being able to determine the stationary structure of a neutron star allows to study its properties, like the parameter space of the equation of state, the mass-radius diagram, and the gravitational wave emission. Moreover, this stationary configuration can be used as initial condition for a much more resource demanding hydrodynamical simulation. A key approximation made for computing the stationary structure of hot and rotating neutron stars is that of barotropicity, namely that all thermodynamical quantities are in a one-to-one relationship, which in turn implies that the specific angular momentum of a fluid element is in a one-to-one relationship with its angular velocity. However, this is a poor approximation for the compact remnant of a core-collapse supernova or of a binary neutron star merger. In this talk I describe how, for the first time, we determine the structure of stationary, hot, rotating neutron stars without the barotropic approximation. To do so, we introduce a potential formulation for the Euler equation, which is a novel technique even in the context of Newtonian stars. Coauthors: Tim Dietrich, Miguel Marques, Stephan Rosswog See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Tue Nov 19 16:28:43 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Tue, 19 Nov 2019 15:28:43 +0000 Subject: [Okc-wp4] [RESCHEDULED] EO meeting Thu Nov 21 @ 15:15 KTH meeting room In-Reply-To: References: Message-ID: <03e4f19bda844301ac25dc3ba3ce19c8@astro.su.se> Notice: The EO meeting time has been rescheduled to 15:15 (2h later than usual) to not coincide with The Oskar Klein Memorial Lecture by Lisa Randall. Dear colleagues, the next EO meeting will take place this Thursday Nov 21 at 15:15 in the KTH meeting room on the 5th floor of the AlbaNova University Centre. Speaker: Giovanni Camelio Title: Rotating neutron stars with non-barotropic thermal profile Abstract: Being able to determine the stationary structure of a neutron star allows to study its properties, like the parameter space of the equation of state, the mass-radius diagram, and the gravitational wave emission. Moreover, this stationary configuration can be used as initial condition for a much more resource demanding hydrodynamical simulation. A key approximation made for computing the stationary structure of hot and rotating neutron stars is that of barotropicity, namely that all thermodynamical quantities are in a one-to-one relationship, which in turn implies that the specific angular momentum of a fluid element is in a one-to-one relationship with its angular velocity. However, this is a poor approximation for the compact remnant of a core-collapse supernova or of a binary neutron star merger. In this talk I describe how, for the first time, we determine the structure of stationary, hot, rotating neutron stars without the barotropic approximation. To do so, we introduce a potential formulation for the Euler equation, which is a novel technique even in the context of Newtonian stars. Coauthors: Tim Dietrich, Miguel Marques, Stephan Rosswog See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Thu Nov 21 11:05:39 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 21 Nov 2019 10:05:39 +0000 Subject: [Okc-wp4] [RESCHEDULED] EO meeting Thu Nov 21 @ 15:15 KTH meeting room In-Reply-To: <03e4f19bda844301ac25dc3ba3ce19c8@astro.su.se> References: , <03e4f19bda844301ac25dc3ba3ce19c8@astro.su.se> Message-ID: <9da166a0392f41169970031d1be589f7@astro.su.se> Reminder of the EO meeting this afternoon, exceptionally at 15:15. --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Andre Schneider Sent: Tuesday, November 19, 2019 4:28:43 PM To: Okc-wp4 at fysik.su.se; people at nordita.org Subject: [Okc-wp4] [RESCHEDULED] EO meeting Thu Nov 21 @ 15:15 KTH meeting room Notice: The EO meeting time has been rescheduled to 15:15 (2h later than usual) to not coincide with The Oskar Klein Memorial Lecture by Lisa Randall. Dear colleagues, the next EO meeting will take place this Thursday Nov 21 at 15:15 in the KTH meeting room on the 5th floor of the AlbaNova University Centre. Speaker: Giovanni Camelio Title: Rotating neutron stars with non-barotropic thermal profile Abstract: Being able to determine the stationary structure of a neutron star allows to study its properties, like the parameter space of the equation of state, the mass-radius diagram, and the gravitational wave emission. Moreover, this stationary configuration can be used as initial condition for a much more resource demanding hydrodynamical simulation. A key approximation made for computing the stationary structure of hot and rotating neutron stars is that of barotropicity, namely that all thermodynamical quantities are in a one-to-one relationship, which in turn implies that the specific angular momentum of a fluid element is in a one-to-one relationship with its angular velocity. However, this is a poor approximation for the compact remnant of a core-collapse supernova or of a binary neutron star merger. In this talk I describe how, for the first time, we determine the structure of stationary, hot, rotating neutron stars without the barotropic approximation. To do so, we introduce a potential formulation for the Euler equation, which is a novel technique even in the context of Newtonian stars. Coauthors: Tim Dietrich, Miguel Marques, Stephan Rosswog See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Mon Dec 2 19:43:34 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Mon, 2 Dec 2019 18:43:34 +0000 Subject: [Okc-wp4] EO meeting Thu Dec 5 @ 13:15 KTH meeting room Message-ID: <77ea7172fdf044b0baddfc5d9d72606c@astro.su.se> Dear colleagues, the next EO meeting will take place this Thursday Dec 5 at 13:15 in the KTH meeting room on the 5th floor of the AlbaNova University Centre. There will be two speakers. Speaker: Joonas Nättilä Title: Physics of turbulence in magnetically-dominated collisionless plasmas Abstract: I'll present our current efforts for understanding the physics of turbulence in magnetized, weakly-collisional plasmas. Such turbulent plasmas can be found, for example, in accretion disk coronae, pulsar wind nebulae, gamma-ray bursts, and magnetically-confined fusion reactors. Our results are based on new massively-parallel fully-kinetic particle-in-cell simulations of decaying turbulence. These simulations offer new insights into the physics of the turbulent energy cascade, particle acceleration mechanisms, and possible radiation signatures from such plasma. Speaker: Ana Sagués Carracedo Title: Detection and follow-up of Kilonovae with the Zwicky Transient Facility Abstract: The first detection of gravitational waves from a binary neutron star merger, GW170817, was associated with a short gamma-ray burst and the kilonova AT2017gfo, localised to nearby galaxy NGC 4993 at around 40 Mpc. The kilonovae was followed-up over the following days and weeks along the electromagnetic spectrum from UV to NIR and it was found The orientation of the merger plane was facing-on, a favorable scenario for the follow-up campaign.This unique discovery gave rise to a new era in multi-messenger astronomy and showed the relevance of these events in astrophysics, cosmology, and nuclear physics. Today, we aim at detecting many more kilonovae to answer the many open questions related to BNS and their use as physics laboratories. However, the observations of kilonovae are generally challenging as these are rare, fast and faint transients. During the talk, I will present the observational challenges and how to study the detectability of kilonovae using survey simulations. I will show results from the Zwicky Transient Facility (ZTF) that quantifies the importance of the observing strategy. I will outline the plans to use the available ZTF all-sky observations to constrain the rates of short-lived transients compatible with kilonovae. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: From andre.schneider at astro.su.se Thu Dec 5 10:38:59 2019 From: andre.schneider at astro.su.se (Andre Schneider) Date: Thu, 5 Dec 2019 09:38:59 +0000 Subject: [Okc-wp4] EO meeting Thu Dec 5 @ 13:15 KTH meeting room In-Reply-To: <77ea7172fdf044b0baddfc5d9d72606c@astro.su.se> References: <77ea7172fdf044b0baddfc5d9d72606c@astro.su.se> Message-ID: <3c736c328cc14cbb9c1f0ede0ea18a57@astro.su.se> Reminder of the EO meeting this afternoon! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Andre Schneider Sent: Monday, December 2, 2019 7:43:34 PM To: Okc-wp4 at fysik.su.se; people at nordita.org Subject: [Okc-wp4] EO meeting Thu Dec 5 @ 13:15 KTH meeting room Dear colleagues, the next EO meeting will take place this Thursday Dec 5 at 13:15 in the KTH meeting room on the 5th floor of the AlbaNova University Centre. There will be two speakers. Speaker: Joonas Nättilä Title: Physics of turbulence in magnetically-dominated collisionless plasmas Abstract: I'll present our current efforts for understanding the physics of turbulence in magnetized, weakly-collisional plasmas. Such turbulent plasmas can be found, for example, in accretion disk coronae, pulsar wind nebulae, gamma-ray bursts, and magnetically-confined fusion reactors. Our results are based on new massively-parallel fully-kinetic particle-in-cell simulations of decaying turbulence. These simulations offer new insights into the physics of the turbulent energy cascade, particle acceleration mechanisms, and possible radiation signatures from such plasma. Speaker: Ana Sagués Carracedo Title: Detection and follow-up of Kilonovae with the Zwicky Transient Facility Abstract: The first detection of gravitational waves from a binary neutron star merger, GW170817, was associated with a short gamma-ray burst and the kilonova AT2017gfo, localised to nearby galaxy NGC 4993 at around 40 Mpc. The kilonovae was followed-up over the following days and weeks along the electromagnetic spectrum from UV to NIR and it was found The orientation of the merger plane was facing-on, a favorable scenario for the follow-up campaign.This unique discovery gave rise to a new era in multi-messenger astronomy and showed the relevance of these events in astrophysics, cosmology, and nuclear physics. Today, we aim at detecting many more kilonovae to answer the many open questions related to BNS and their use as physics laboratories. However, the observations of kilonovae are generally challenging as these are rare, fast and faint transients. During the talk, I will present the observational challenges and how to study the detectability of kilonovae using survey simulations. I will show results from the Zwicky Transient Facility (ZTF) that quantifies the importance of the observing strategy. I will outline the plans to use the available ZTF all-sky observations to constrain the rates of short-lived transients compatible with kilonovae. See you there! --------------------------------- André da Silva Schneider Department of Astronomy Stockholm University -------------- next part -------------- An HTML attachment was scrubbed... URL: