Gagliano, Alexander and Izzo, Luca and Kilpatrick, Charles D. and Mockler, Brenna and Jacobson-Galán, Wynn Vicente and Terreran, Giacomo and Dimitriadis, Georgios and Zenati, Yossef and Auchettl, Katie and Drout, Maria R. and Narayan, Gautham and Foley, Ryan J. and Margutti, R. and Rest, Armin and Jones, D. O. and Aganze, Christian and Aleo, Patrick D. and Burgasser, Adam J. and Coulter, D. A. and Gerasimov, Roman and Gall, Christa and Hjorth, Jens and Hsu, Chih-Chun and Magnier, Eugene A. and Mandel, Kaisey S. and Piro, Anthony L. and Rojas-Bravo, César and Siebert, Matthew R. and Stacey, Holland and Stroh, Michael Cullen and Swift, Jonathan J. and Taggart, Kirsty and Tinyanont, Samaporn (2022) An Early-time Optical and Ultraviolet Excess in the Type-Ic SN 2020oi. The Astrophysical Journal, 924 (2): 55. ISSN 0004-637X
Full text not available from this repository.Abstract
We present photometric and spectroscopic observations of Supernova 2020oi (SN 2020oi), a nearby (∼17 Mpc) type-Ic supernova (SN Ic) within the grand-design spiral M100. We undertake a comprehensive analysis to characterize the evolution of SN 2020oi and constrain its progenitor system. We detect flux in excess of the fireball rise model δ t ≈ 2.5 days from the date of explosion in multiband optical and UV photometry from the Las Cumbres Observatory and the Neil Gehrels Swift Observatory, respectively. The derived SN bolometric luminosity is consistent with an explosion with M ej = 0.81 ± 0.03 M o˙, E k = 0.79 ± 0.09 × 1051 erg s-1, and M Ni56 = 0.08 ± 0.02 M o˙. Inspection of the event's decline reveals the highest Δm 15,bol reported for a stripped-envelope event to date. Modeling of optical spectra near event peak indicates a partially mixed ejecta comparable in composition to the ejecta observed in SN 1994I, while the earliest spectrum shows signatures of a possible interaction with material of a distinct composition surrounding the SN progenitor. Further, Hubble Space Telescope pre-explosion imaging reveals a stellar cluster coincident with the event. From the cluster photometry, we derive the mass and age of the SN progenitor using stellar evolution models implemented in the BPASS library. Our results indicate that SN 2020oi occurred in a binary system from a progenitor of mass M ZAMS ≈ 9.5 ± 1.0 M o˙, corresponding to an age of 27 ± 7 Myr. SN 2020oi is the dimmest SN Ic event to date for which an early-time flux excess has been observed, and the first in which an early excess is unlikely to be associated with shock cooling.