The rise and fall of the iron-strong nuclear transient PS16dtm

Astronomy & Astrophysics EDP Sciences 669 (2023) a140

Authors:

T Petrushevska, G Leloudas, D Ilić, M Bronikowski, P Charalampopoulos, GK Jaisawal, E Paraskeva, M Pursiainen, N Rakić, S Schulze, K Taggart, CK Wedderkopp, JP Anderson, T de Boer, K Chambers, TW Chen, G Damljanović, M Fraser, H Gao, A Gomboc, M Gromadzki, N Ihanec, K Maguire, B Marčun, TE Müller-Bravo, M Nicholl, F Onori, TM Reynolds, SJ Smartt, J Sollerman, KW Smith, T Wevers, Ł Wyrzykowski

Late-time H/He-poor Circumstellar Interaction in the Type Ic Supernova SN 2021ocs: An Exposed Oxygen–Magnesium Layer and Extreme Stripping of the Progenitor*

The Astrophysical Journal Letters American Astronomical Society 941:2 (2022) L32-L32

Authors:

H Kuncarayakti, K Maeda, L Dessart, T Nagao, M Fulton, CP Gutiérrez, ME Huber, DR Young, R Kotak, S Mattila, JP Anderson, L Ferrari, G Folatelli, H Gao, E Magnier, KW Smith, S Srivastav

Abstract:

Abstract Supernova (SN) 2021ocs was discovered in the galaxy NGC 7828 (z = 0.01911) within the interacting system Arp 144 and subsequently classified as a normal Type Ic SN around peak brightness. Very Large Telescope/FORS2 observations in the nebular phase at 148 days reveal that the spectrum is dominated by oxygen and magnesium emission lines of different transitions and ionization states: O i, [O i], [O ii], [O iii], Mg i, and Mg ii. Such a spectrum has no counterpart in the literature, though it bears a few features similar to those of some interacting Type Ibn and Icn SNe. Additionally, SN 2021ocs showed a blue color, (gr) ≲ −0.5 mag, after the peak and up to late phases, atypical for a Type Ic SN. Together with the nebular spectrum, this suggests that SN 2021ocs underwent late-time interaction with an H/He-poor circumstellar medium (CSM) resulting from the pre-SN progenitor mass loss during its final ∼1000 days. The strong O and Mg lines and the absence of strong C and He lines suggest that the progenitor star’s O–Mg layer is exposed, which places SN 2021ocs as the most extreme case of a massive progenitor star’s envelope stripping in interacting SNe, followed by Type Icn (stripped C–O layer) and Ibn (stripped He-rich layer) SNe. This is the first time such a case is reported in the literature. The SN 2021ocs emphasizes the importance of late-time spectroscopy of SNe, even for those classified as normal events, to reveal the inner ejecta and progenitor star’s CSM and mass loss.

The Birth of a Relativistic Jet Following the Disruption of a Star by a Cosmological Black Hole

(2022)

Authors:

Dheeraj R Pasham, Matteo Lucchini, Tanmoy Laskar, Benjamin P Gompertz, Shubham Srivastav, Matt Nicholl, Stephen J Smartt, James CA Miller-Jones, Kate D Alexander, Rob Fender, Graham P Smith, Michael D Fulton, Gulab Dewangan, Keith Gendreau, Eric R Coughlin, Lauren Rhodes, Assaf Horesh, Sjoert van Velzen, Itai Sfaradi, Muryel Guolo, N Castro Segura, Aysha Aamer, Joseph P Anderson, Iair Arcavi, Sean J Brennan, Kenneth Chambers, Panos Charalampopoulos, Ting-Wan Chen, A Clocchiatti, Thomas de Boer, Michel Dennefeld, Elizabeth Ferrara, Lluis Galbany, Hua Gao, James H Gillanders, Adelle Goodwin, Mariusz Gromadzki, M Huber, Peter G Jonker, Manasvita Joshi, Erin Kara, Thomas L Killestein, Peter Kosec, Daniel Kocevski, Giorgos Leloudas, Chien-Cheng Lin, Raffaella Margutti, Seppo Mattila, Thomas Moore, Tomas Muller-Bravo, Chow-Choong Ngeow, Samantha Oates, Francesca Onori, Yen-Chen Pan, Miguel Perez-Torres, Priyanka Rani, Ronald Remillard, Evan J Ridley, Steve Schulze, Xinyue Sheng, Luke Shingles, Ken W Smith, James Steiner, Richard Wainscoat, Thomas Wevers, Sheng Yang

The rise and fall of the iron-strong nuclear transient PS16dtm

(2022)

Authors:

T Petrushevska, G Leloudas, D Ilic, M Bronikowski, P Charalampopoulos, GK Jaisawal, E Paraskeva, M Pursiainen, N Rakic, S Schulze, K Taggart, CK Wedderkopp, JP Anderson, T de Boer, K Chambers, TW Chen, G Damljanovic, M Fraser, H Gao, A Gomboc, M Gromadzki, N Ihanec, K Maguire, B Marcun, TE Muller-Bravo, M Nicholl, F Onori, TM Reynolds, SJ Smartt, J Sollerman, KW Smith, T Wevers, L Wyrzykowski

Evidence for non-merger co-evolution of galaxies and their supermassive black holes

(2022)

Authors:

Rj Smethurst, Rs Beckmann, Bd Simmons, A Coil, J Devriendt, Y Dubois, Il Garland, Cj Lintott, G Martin, S Peirani