Journal article
SN 2020acat: an energetic fast rising Type IIb supernova
Liverpool John Moores University1
Department of Space Research and Technology, Technical University of Denmark2
Stockholm University3
Institute of Space Studies of Catalonia4
University of Warsaw5
Harvard-Smithsonian Center for Astrophysics6
Cardiff University7
CSIC - Institute of Space Sciences8
University of Birmingham9
Nordic Optical Telescope10
Universidad Nacional de La Plata11
University of Hawai'i at Mānoa12
University of Copenhagen13
Inter-University Centre for Astronomy and Astrophysics India14
Queen's University Belfast15
European Southern Observatory16
Tel Aviv University17
Astronomical Observatory of Padua18
University of Washington19
University of California at Santa Barbara20
Tsinghua University21
Astrophysics and Atmospheric Physics, Department of Space Research and Technology, Technical University of Denmark22
...and 12 moreThe ultraviolet (UV) and near-infrared (NIR) photometric and optical spectroscopic observations of SN 2020acat covering ∼250 d after explosion are presented here. Using the fast rising photometric observations, spanning from the UV to NIR wavelengths, a pseudo-bolometric light curve was constructed and compared to several other well-observed Type IIb supernovae (SNe IIb).
SN 2020acat displayed a very short rise time reaching a peak luminosity of Log10(L)=42.49±0.17ergs−1 in only ∼14.6 ± 0.3 d. From modelling of the pseudo-bolometric light curve, we estimated a total mass of 56Ni synthesized by SN 2020acat of MNi = 0.13 ± 0.03 M⊙, with an ejecta mass of Mej = 2.3 ± 0.4 M⊙ and a kinetic energy of Ek = 1.2 ± 0.3 × 1051 erg.
The optical spectra of SN 2020acat display hydrogen signatures well into the transitional period (≳ 100 d), between the photospheric and the nebular phases. The spectra also display a strong feature around 4900 Å that cannot be solely accounted for by the presence of the Fe ii 5018 line. We suggest that the Fe ii feature was augmented by He i 5016 and possibly by the presence of N ii 5005.
From both photometric and spectroscopic analysis, we inferred that the progenitor of SN 2020acat was an intermediate-mass compact star with an MZAMS of 15–20 M⊙.
| Language: | English |
|---|---|
| Year: | 2022 |
| Pages: | 5540-5558 |
| ISSN: | 13652966 and 00358711 |
| Types: | Journal article |
| DOI: | 10.1093/mnras/stac1192 |
| ORCIDs: | 0000-0001-7186-105X , 0000-0001-8290-2881 , 0000-0002-5221-7557 , 0000-0002-3256-0016 , 0000-0002-4924-444X , 0000-0002-1296-6887 , 0000-0002-1650-1518 , 0000-0002-3968-4409 , 0000-0002-3664-8082 , 0000-0003-3939-7167 , 0000-0003-4254-2724 , 0000-0002-1022-6463 , 0000-0002-3697-2616 and Charalampopoulos, P. |
