From haakon.andresen at astro.su.se Thu Jan 18 09:23:59 2024 From: haakon.andresen at astro.su.se (Haakon Andresen) Date: Thu, 18 Jan 2024 08:23:59 +0000 Subject: [Okc-wp4] EO seminar on the 25th of January Message-ID: <43e1877ae53c4c74aa4e0ffae451a48a@astro.su.se> Dear everyone, Next week we will have the first EO seminar of the year. I look forward to seeing you all there. Speaker: Deepika Venkattu When and where: Thursday 25 of Januar, 13:00 in A5:1003 Title: Radio supernovae - a low-frequency perspective Abstract: Supernovae are the explosive end stages of stars and despite being well-studied, they still pose unanswered questions. In the radio, we see synchrotron emission from the interaction of the supernova ejecta with the dense circumstellar material (CSM). With the onset of the Square Kilometre Array era, there is renewed focus on the low-frequency radio sky, with many technological advancements from the likes of GMRT, VLITE, MWA and the recent Very Long Baseline Interferometry pipeline at 150 MHz with the International LOFAR Telescope. In this talk, I will present the topic of my PhD - exploring the nascent field of supernovae science at low radio frequencies with LOFAR. We will discuss technical challenges and my work using LOFAR to study supernovae in M51 and M31. Such low-frequency studies and technical advancements will help us explore existing research questions but also pave the way for new science at low frequencies. Best, Haakon (on behalf of the organisers ) -------------- next part -------------- An HTML attachment was scrubbed... URL: From haakon.andresen at astro.su.se Wed Jan 24 09:25:34 2024 From: haakon.andresen at astro.su.se (Haakon Andresen) Date: Wed, 24 Jan 2024 08:25:34 +0000 Subject: [Okc-wp4] Upcoming EO seminars Message-ID: <05c169bb7cd0439bbfdf12eddfa80212@astro.su.se> Dear Everyone, The EO seminar schedule for the first half of the spring semester is ready. We start tomorrow with Deepika Venkattu, at 13:00 in A5:1003. As always, let us know if you want to suggest a speaker. We have room for extra seminars in between our regular meetings if something comes up. The seminars are listed here https://indico.fysik.su.se/category/289/ and you can import them directly into your calendar. Best, Haakon (on behalf of the organisers) Schedule: January Jan 25th Deepika Venkattu, Radio supernovae - a low-frequency perspective February Feb 15th: Daniel Siegel Feb 29th: Barteld van Baal, Developing spectral synthesis in 3D March Mar 14th: Seán Brennan, Early Warning Signs: Progenitor Activity Preceding Interacting Supernovae Mar 28th: Ludovica Crosato Menegazzi, Variety of disk wind-driven explosions in massive rotating stars April Apr 11th: Anjasha Gangopadhyay Apr 25th: TBA -------------- next part -------------- An HTML attachment was scrubbed... URL: From haakon.andresen at astro.su.se Mon Feb 12 08:26:45 2024 From: haakon.andresen at astro.su.se (Haakon Andresen) Date: Mon, 12 Feb 2024 07:26:45 +0000 Subject: [Okc-wp4] EO seminar on the 15th Message-ID: Dear everyone, This weeks seminar will be given by Dan Siegel, who is visiting Stockholm this week. Abstract and title below. Best, Haakon (on behalf of the the organisers) When and where: Thursday 15th of February, 13:00 in A5:1003 Speaker: Daniel Siegel Title: Jets from neutron star mergers and LVK O3 constraints on heavy-element formation Abstract: This talk reviews recent developments related to simulations of neutron-star mergers, the generation of kilonovae, and the synthesis of rapid neutron capture (r-process) elements in the Universe. In particular, the talk will discuss recent constraints on r-process nucleosynthesis from the O3 run of the LVK gravitational-wave detectors. It will also focus on recently identified magnetohydrodynamic jet-formation mechanisms in neutron-star mergers and their implications for the generation of GW170817-like massive blue kilonovae and short gamma-ray bursts. -------------- next part -------------- An HTML attachment was scrubbed... URL: From smaranika.banerjee at astro.su.se Fri Feb 23 18:07:41 2024 From: smaranika.banerjee at astro.su.se (Smaranika Banerjee) Date: Fri, 23 Feb 2024 17:07:41 +0000 Subject: [Okc-wp4] Extreme object biweekly meeting time has changed from Thursdays 13:00 to 13:15 Message-ID: Dear all, This is Smaranika on behalf of extreme object group meeting organisers. I am mailing to notify that as we discussed last week, our meeting time has changed from Thursdays 13:00 to 13:15 from now on. This is to avoid rushing back from lunch :) See you all next week. Thank you very much. Kind regards, Smaranika =============================================================== Dr. Smaranika Banerjee Astronomy Department, Stockholm University Email: smaranika.banerjee at astro.su.se Old email: smaranikab at astr.tohoku.ac.jp Website: https://sites.google.com/view/smaranikabanerjee/welcome?authuser=0 Zoom: https://stockholmuniversity.zoom.us/j/3760189321 =============================================================== -------------- next part -------------- An HTML attachment was scrubbed... URL: From smaranika.banerjee at astro.su.se Mon Feb 26 15:11:07 2024 From: smaranika.banerjee at astro.su.se (Smaranika Banerjee) Date: Mon, 26 Feb 2024 14:11:07 +0000 Subject: [Okc-wp4] Talk by Bart at extreme object group meeting this Thursday 29th of February, 13:15 in A5:1003 Message-ID: <2738d5a8cccf48709b74fa84cfbbc891@astro.su.se> Dear all, This is Smaranika on behalf of extreme object group meeting organisers. This is a kind reminder of this weeks talk! When and where: Thursday 29th of February, 13:15 in A5:1003 Speaker: Bart van Baal Title:Developing spectral synthesis in 3D Abstract: The nebular phase of a supernova is a phase rich with information on the ejecta composition and with it, the progenitor system. With many intricate physical processes playing important roles, making models for the nebular phase is a complex task which is usually only done in 1D. Recently however, the first late- time 3D core-collapse models have become available to use as input models for nebular phase calculations. Using these 3D inputs requires the development of a 3D nebular phase code. In this talk I will both highlight my latest results with my 3D code ExTraSS (EXplosive TRAnsient Spectral Simulator) as well as outline how I approached the designing of this code, as the step from 1D to 3D is computationally challenging for these detailed nebular phase calculations. Note that our meeting time has changed from Thursdays 13:00 to 13:15 from now on. See you all this week. Kind regards, Smaranika =============================================================== Dr. Smaranika Banerjee Astronomy Department, Stockholm University Email: smaranika.banerjee at astro.su.se Old email: smaranikab at astr.tohoku.ac.jp Website: https://sites.google.com/view/smaranikabanerjee/welcome?authuser=0 Zoom: https://stockholmuniversity.zoom.us/j/3760189321 =============================================================== -------------- next part -------------- An HTML attachment was scrubbed... URL: From haakon.andresen at astro.su.se Tue Mar 12 10:10:29 2024 From: haakon.andresen at astro.su.se (Haakon Andresen) Date: Tue, 12 Mar 2024 09:10:29 +0000 Subject: [Okc-wp4] EO seminar 14th at 13:15 A5:1003 Message-ID: <27fa8ade0a47489fb58a3e8b1329ebc2@astro.su.se> Dear everyone, This week Seán Brennan will talk about supernova precursor signals. When: 13:15 Thursday 14th of March Where: A5:1003 Speaker: Seán Brennan Title: Early Warning Signs: Precursor Activity Preceding Supernova Abstract: Core-collapse supernovae are generally observed after the massive star has been destroyed, with information about the progenitor star inferred indirectly from the appearance and evolution of the supernova. Over the last decade, researchers have identified energetic activity at the locations of supernova explosions in the years leading up to core collapse in historical archives. These events are typically attributed to the massive progenitor star undergoing some form of activity via currently unknown mechanisms. One challenge when observing these precursor events is the uncertainty surrounding when or if the actual supernova explosion will occur. This uncertainty often makes us hesitant to allocate valuable telescope time. In this talk, I will present a growing sample of objects that demonstrate that some massive stars exhibit variability weeks to months before their final supernova. Through this work, we may be able to obtain advance warning of an impending supernova, allowing for high-reward observations and, to some extent, the ability to predict the final death of a massive star. Best, Haakon (on behalf of the organizers) PS: If anyone wish to join on zoom https://stockholmuniversity.zoom.us/j/3575421837 -------------- next part -------------- An HTML attachment was scrubbed... URL: From haakon.andresen at astro.su.se Tue Mar 26 08:47:17 2024 From: haakon.andresen at astro.su.se (Haakon Andresen) Date: Tue, 26 Mar 2024 07:47:17 +0000 Subject: [Okc-wp4] EO talk on the 28th Message-ID: <66de1ad9aabd4bf589f5b4bff8f0469b@astro.su.se> Dear everyone, The next EO seminar will take place on Thursday. Ludovica Crosato Menegazzi is visiting us from the Albert Einstein Institute. When: 13:15 Thursday 28th of March Where: A5:1003 Speaker: Ludovica Crosato Menegazzi Title: Variety of disk wind-driven explosions in massive rotating stars Abstract: At the end of its evolution, the collapse of a massive star's core into a proto-neutron star is the starting point for a complex sequence of events with many possible outcomes. Specifically, very compact and rotating stars with a high mass (M>16M_sun), are likely to create a so-called ``failed core-collapse supernova'', forming a black hole surrounded by an accreting disk. It has been shown that the disk wind generated through viscous dissipation inside the disk may be the source of high energy (E_expl>10^52 erg) supernovae with a high 56Ni mass (M_56Ni> 0.1 M_sun). In this scenario, the properties of the ejecta and the 56Ni production are strongly related to the wind injection from the accretion disk. In this talk, I will analyze these properties, investigating the impact of the disk mass and energy injected from the system on the final ejecta. I will focus on observational properties such as the explosion energy, the ejecta mass, and the 56Ni mass produced for different progenitor model. I will then show the strong correlation between the explosion energy and the ejecta mass, and compare our results for the56Ni mass distribution with observational data, focusing on the late-phase mass ejection after BH formation. Best, Haakon (on behalf of the organizers) -------------- next part -------------- An HTML attachment was scrubbed... URL: From smaranika.banerjee at astro.su.se Tue Apr 9 11:10:42 2024 From: smaranika.banerjee at astro.su.se (Smaranika Banerjee) Date: Tue, 9 Apr 2024 09:10:42 +0000 Subject: [Okc-wp4] OKC -EO seminar this week Message-ID: <164be4698708480bb7c25a01a604b631@astro.su.se> Dear all, This is Smaranika on behalf of extreme object group meeting organisers. We will have our OKC -EO seminar this week. When and where: Thursday 11th April, 13:15 in A5:1003 Speaker: Anjasha Gangopadhyay, a new postdoc in Jesper’s group, welcome! Title: Investigating a group of supernovae with diminishing hydrogen envelope Abstract: In this talk, I will derive a continuity in the outer layers of Hydrogen/Helium in a group of stripped envelope supernovae (SNe) which loose their outer envelope and a group of interacting SNe which gain their outer envelope through interaction with a nearby circumstellar medium (CSM). Through our long term observing campaigns, we have studied few representative members of these subclasses indicating that the members are not really distinct but are linked by a continuum of outer envelope. We used the probe of light curve modelling to estimate the physical parameters associated with the explosions like the Ni-mass, ejecta mass and energies of the explosions of these SNe while spectral modelling helped to constrain the spectral parameters like elemental abundances and velocities. For the interacting SNe, modelling also helped us to infer the CSM mass, radius and geometry. Along with probing the progenitor scenarios and mass-loss history of these events which are highly debated, we have now investigated some new objects which highlight the fact that these members are not really distinct and are divided based on the outer continuum layer. Currently, big telescopes with larger diameters will help to see whether stripped envelope supernovae can become interacting on a longer time scale. Also, a more robust search will help to find such transitioning members and thereby probing their progenitor systems. Thank you very much. Hope to see many of you there. Kind regards, Smaranika (on behalf of the organizers) =============================================================== Dr. Smaranika Banerjee Astronomy Department, Stockholm University Email: smaranika.banerjee at astro.su.se Old email: smaranikab at astr.tohoku.ac.jp Website: https://sites.google.com/view/smaranikabanerjee/welcome?authuser=0 Zoom: https://stockholmuniversity.zoom.us/j/3760189321 =============================================================== -------------- next part -------------- An HTML attachment was scrubbed... URL: From smaranika.banerjee at astro.su.se Thu Apr 11 10:50:46 2024 From: smaranika.banerjee at astro.su.se (Smaranika Banerjee) Date: Thu, 11 Apr 2024 08:50:46 +0000 Subject: [Okc-wp4] OKC -EO seminar this week In-Reply-To: <164be4698708480bb7c25a01a604b631@astro.su.se> References: <164be4698708480bb7c25a01a604b631@astro.su.se> Message-ID: Dear all, A gentle Reminder of the talk today at 1315! Let us know if anyone wants zoom. Kind regards, Smaranika (on behalf of the organizers) =============================================================== Dr. Smaranika Banerjee Astronomy Department, Stockholm University Email: smaranika.banerjee at astro.su.se Old email: smaranikab at astr.tohoku.ac.jp Website: https://sites.google.com/view/smaranikabanerjee/welcome?authuser=0 Zoom: https://stockholmuniversity.zoom.us/j/3760189321 =============================================================== ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Smaranika Banerjee via Okc-wp4-at-fysik.su.se Sent: Tuesday, April 9, 2024 11:10:42 AM To: Okc-wp4 at fysik.su.se Cc: Anjasha Gangopadhyay Subject: [Okc-wp4] OKC -EO seminar this week Dear all, This is Smaranika on behalf of extreme object group meeting organisers. We will have our OKC -EO seminar this week. When and where: Thursday 11th April, 13:15 in A5:1003 Speaker: Anjasha Gangopadhyay, a new postdoc in Jesper’s group, welcome! Title: Investigating a group of supernovae with diminishing hydrogen envelope Abstract: In this talk, I will derive a continuity in the outer layers of Hydrogen/Helium in a group of stripped envelope supernovae (SNe) which loose their outer envelope and a group of interacting SNe which gain their outer envelope through interaction with a nearby circumstellar medium (CSM). Through our long term observing campaigns, we have studied few representative members of these subclasses indicating that the members are not really distinct but are linked by a continuum of outer envelope. We used the probe of light curve modelling to estimate the physical parameters associated with the explosions like the Ni-mass, ejecta mass and energies of the explosions of these SNe while spectral modelling helped to constrain the spectral parameters like elemental abundances and velocities. For the interacting SNe, modelling also helped us to infer the CSM mass, radius and geometry. Along with probing the progenitor scenarios and mass-loss history of these events which are highly debated, we have now investigated some new objects which highlight the fact that these members are not really distinct and are divided based on the outer continuum layer. Currently, big telescopes with larger diameters will help to see whether stripped envelope supernovae can become interacting on a longer time scale. Also, a more robust search will help to find such transitioning members and thereby probing their progenitor systems. Thank you very much. Hope to see many of you there. Kind regards, Smaranika (on behalf of the organizers) =============================================================== Dr. Smaranika Banerjee Astronomy Department, Stockholm University Email: smaranika.banerjee at astro.su.se Old email: smaranikab at astr.tohoku.ac.jp Website: https://sites.google.com/view/smaranikabanerjee/welcome?authuser=0 Zoom: https://stockholmuniversity.zoom.us/j/3760189321 =============================================================== -------------- next part -------------- An HTML attachment was scrubbed... URL: From haakon.andresen at astro.su.se Fri Apr 19 14:55:12 2024 From: haakon.andresen at astro.su.se (Haakon Andresen) Date: Fri, 19 Apr 2024 12:55:12 +0000 Subject: [Okc-wp4] EO seimar on the 25th of April Message-ID: Dear Everyone, Next week we will have a seminar by James Gillanders. Best, Haakon (on behalf of the organizers) When and where: Thursday 25th April, 13:15 in A5:1003 Speaker: James Gillanders, Postdoc at Oxford Title: Identifying heavy r-process elements in the spectra of two compact binary mergers Abstract: Kilonovae are the optical counterpart associated with the radioactive decay of an ensemble of freshly synthesised unstable isotopes produced by the rapid neutron-capture process (r-process). The r-process is responsible for synthesising approximately half of all elements beyond the iron peak. Direct observations of r-process nucleosynthesis are limited; to date, the only observed production site remains binary neutron star mergers. These merger systems evolve rapidly and are intrinsically faint compared to virtually all other known extragalactic transients, and so remain elusive to wide-field surveys optimised to search for such events. While there are proposed detections of ~10 kilonova events, only two of these have been observed spectroscopically – AT2017gfo/GRB170817A and AT2023vfi/GRB230307A. In this talk, I will present the spectral observations that exist for kilonovae, with a focus on the heavy r-process element identifications that can be extracted from such observations. Specifically, I will present the results of my recent work to constrain the composition of AT2017gfo, both at early and late times. I will also highlight new work on the exciting JWST spectral observations of AT2023vfi, and what we can extract from these near-infrared, late-time observations. -------------- next part -------------- An HTML attachment was scrubbed... URL: From stephan.rosswog at astro.su.se Fri Apr 19 17:09:19 2024 From: stephan.rosswog at astro.su.se (Stephan Rosswog) Date: Fri, 19 Apr 2024 15:09:19 +0000 Subject: [Okc-wp4] EO seimar on the 25th of April In-Reply-To: References: Message-ID: Hi Haakon I’d like to join via zoom if that is possible. Cheers Stephan On 19 Apr 2024, at 14:55, Haakon Andresen via Okc-wp4-at-fysik.su.se > wrote: Dear Everyone, Next week we will have a seminar by James Gillanders. Best, Haakon (on behalf of the organizers) When and where: Thursday 25th April, 13:15 in A5:1003 Speaker: James Gillanders, Postdoc at Oxford Title: Identifying heavy r-process elements in the spectra of two compact binary mergers Abstract: Kilonovae are the optical counterpart associated with the radioactive decay of an ensemble of freshly synthesised unstable isotopes produced by the rapid neutron-capture process (r-process). The r-process is responsible for synthesising approximately half of all elements beyond the iron peak. Direct observations of r-process nucleosynthesis are limited; to date, the only observed production site remains binary neutron star mergers. These merger systems evolve rapidly and are intrinsically faint compared to virtually all other known extragalactic transients, and so remain elusive to wide-field surveys optimised to search for such events. While there are proposed detections of ~10 kilonova events, only two of these have been observed spectroscopically – AT2017gfo/GRB170817A and AT2023vfi/GRB230307A. In this talk, I will present the spectral observations that exist for kilonovae, with a focus on the heavy r-process element identifications that can be extracted from such observations. Specifically, I will present the results of my recent work to constrain the composition of AT2017gfo, both at early and late times. I will also highlight new work on the exciting JWST spectral observations of AT2023vfi, and what we can extract from these near-infrared, late-time observations. ------------------------------------------------- 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 haakon.andresen at astro.su.se Fri Apr 19 18:37:45 2024 From: haakon.andresen at astro.su.se (Haakon Andresen) Date: Fri, 19 Apr 2024 16:37:45 +0000 Subject: [Okc-wp4] EO seimar on the 25th of April In-Reply-To: References: , Message-ID: <33ca0ad737624398990456bf8abe8b0d@astro.su.se> I will make sure we set it up and send you a link in advance. ________________________________ From: Stephan Rosswog Sent: 19 April 2024 17:09:19 To: Haakon Andresen Cc: EO meeting email Subject: Re: [Okc-wp4] EO seimar on the 25th of April Hi Haakon I’d like to join via zoom if that is possible. Cheers Stephan On 19 Apr 2024, at 14:55, Haakon Andresen via Okc-wp4-at-fysik.su.se > wrote: Dear Everyone, Next week we will have a seminar by James Gillanders. Best, Haakon (on behalf of the organizers) When and where: Thursday 25th April, 13:15 in A5:1003 Speaker: James Gillanders, Postdoc at Oxford Title: Identifying heavy r-process elements in the spectra of two compact binary mergers Abstract: Kilonovae are the optical counterpart associated with the radioactive decay of an ensemble of freshly synthesised unstable isotopes produced by the rapid neutron-capture process (r-process). The r-process is responsible for synthesising approximately half of all elements beyond the iron peak. Direct observations of r-process nucleosynthesis are limited; to date, the only observed production site remains binary neutron star mergers. These merger systems evolve rapidly and are intrinsically faint compared to virtually all other known extragalactic transients, and so remain elusive to wide-field surveys optimised to search for such events. While there are proposed detections of ~10 kilonova events, only two of these have been observed spectroscopically – AT2017gfo/GRB170817A and AT2023vfi/GRB230307A. In this talk, I will present the spectral observations that exist for kilonovae, with a focus on the heavy r-process element identifications that can be extracted from such observations. Specifically, I will present the results of my recent work to constrain the composition of AT2017gfo, both at early and late times. I will also highlight new work on the exciting JWST spectral observations of AT2023vfi, and what we can extract from these near-infrared, late-time observations. ------------------------------------------------- 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 smaranika.banerjee at astro.su.se Thu Apr 25 11:06:14 2024 From: smaranika.banerjee at astro.su.se (Smaranika Banerjee) Date: Thu, 25 Apr 2024 09:06:14 +0000 Subject: [Okc-wp4] EO seimar on the 25th of April In-Reply-To: <33ca0ad737624398990456bf8abe8b0d@astro.su.se> References: , , <33ca0ad737624398990456bf8abe8b0d@astro.su.se> Message-ID: <0308a1bc8e604344a05fcfce811ab09c@astro.su.se> Dear all, Reminder of the talk today. We will use the following zoom link https://stockholmuniversity.zoom.us/j/3760189321 Thank you very much. Kind regards, Smaranika (on behalf of the organisers) =============================================================== Dr. Smaranika Banerjee Astronomy Department, Stockholm University Email: smaranika.banerjee at astro.su.se Old email: smaranikab at astr.tohoku.ac.jp Website: https://sites.google.com/view/smaranikabanerjee/welcome?authuser=0 Zoom: https://stockholmuniversity.zoom.us/j/3760189321 =============================================================== ________________________________ From: Okc-wp4-at-fysik.su.se on behalf of Haakon Andresen via Okc-wp4-at-fysik.su.se Sent: Friday, April 19, 2024 6:37:45 PM To: Stephan Rosswog Cc: EO meeting email Subject: Re: [Okc-wp4] EO seimar on the 25th of April I will make sure we set it up and send you a link in advance. ________________________________ From: Stephan Rosswog Sent: 19 April 2024 17:09:19 To: Haakon Andresen Cc: EO meeting email Subject: Re: [Okc-wp4] EO seimar on the 25th of April Hi Haakon I’d like to join via zoom if that is possible. Cheers Stephan On 19 Apr 2024, at 14:55, Haakon Andresen via Okc-wp4-at-fysik.su.se > wrote: Dear Everyone, Next week we will have a seminar by James Gillanders. Best, Haakon (on behalf of the organizers) When and where: Thursday 25th April, 13:15 in A5:1003 Speaker: James Gillanders, Postdoc at Oxford Title: Identifying heavy r-process elements in the spectra of two compact binary mergers Abstract: Kilonovae are the optical counterpart associated with the radioactive decay of an ensemble of freshly synthesised unstable isotopes produced by the rapid neutron-capture process (r-process). The r-process is responsible for synthesising approximately half of all elements beyond the iron peak. Direct observations of r-process nucleosynthesis are limited; to date, the only observed production site remains binary neutron star mergers. These merger systems evolve rapidly and are intrinsically faint compared to virtually all other known extragalactic transients, and so remain elusive to wide-field surveys optimised to search for such events. While there are proposed detections of ~10 kilonova events, only two of these have been observed spectroscopically – AT2017gfo/GRB170817A and AT2023vfi/GRB230307A. In this talk, I will present the spectral observations that exist for kilonovae, with a focus on the heavy r-process element identifications that can be extracted from such observations. Specifically, I will present the results of my recent work to constrain the composition of AT2017gfo, both at early and late times. I will also highlight new work on the exciting JWST spectral observations of AT2023vfi, and what we can extract from these near-infrared, late-time observations. ------------------------------------------------- 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: