| Title: |
SN 2020acat: A purr-fect example of a fast rising Type IIb Supernova |
| Authors: |
Medler, K., Mazzali, P. A., Teffs, J., Ashall, C., Anderson, J. P., Arcavi, I., Benetti, S., Bostroem, K. A., Burke, J., Cai, Y. -Z., Charalampopoulos, P., Elias-Rosa, N., Ergon, M., Galbany, L., Gromadzki, M., Hiramatsu, D., Howell, D. A., Inserra, C., Lundqvist, P., McCully, C., Müller-Bravo, T., Newsome, M., Nicholl, M., Gonzalez, E. Padilla, Paraskeva, E., Pastorello, A., Pellegrino, C., Pessi, P. J., Requitti, A., Reynolds, T. M., Roy, R., Terreran, G., Tomasella, L., Young, D. R. |
| Publication Year: |
2022 |
| Collection: |
Astrophysics |
| Subject Terms: |
Astrophysics - High Energy Astrophysical Phenomena |
| More Details: |
The Ultra-Violet (UV) and Near Infrared (NIR) photometric and optical spectroscopic observations of SN 2020acat covering $\sim \! \! 250$ days 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 $\mathrm{Log_{10}}(L) = 42.49 \pm 0.15 \, \mathrm{erg \, s^{-1}}$ in only $\sim \! \! 14.6 \pm 0.3$ days. From modelling of the pseudo-bolometric light curve, we estimated a total mass of $^{56} \mathrm{Ni}$ synthesised by SN 2020acat of $0.13 \pm 0.02 \, \mathrm{M_{\odot}}$, with an ejecta mass of $2.3 \pm 0.3 \, \mathrm{M_{\odot}}$ and a kinetic energy of $1.2 \pm 0.2 \times 10^{51}$ erg. The optical spectra of SN 2020acat display hydrogen signatures well into the transitional period ($\gtrsim 100$ days), between the photospheric and the nebular phases. The spectra also display a strong feature around $4900 \, \r{A}$ that cannot be solely accounted for by the presence of the $\mathrm{Fe_{II}}$ $5018$ line. We suggest that the $\mathrm{Fe_{II}}$ feature was augmented by $\mathrm{He_{I}}$ $5016$ and possibly by the presence of $\mathrm{N_{II}}$ $5005$. From both photometric and spectroscopic analysis, we inferred that the progenitor of SN\,2020acat was an intermediate mass compact star with a $M_\mathrm{ZAMS}$ of $18 - 22 \, \mathrm{M_{\odot}}$.
Comment: 18 pages, 13 figures |
| Document Type: |
Working Paper |
| Access URL: |
http://arxiv.org/abs/2201.06991 |
| Accession Number: |
edsarx.2201.06991 |
| Database: |
arXiv |
