The Final Months of Massive Star Evolution from the Circumstellar Environment around SN Ic 2020oi

Maeda, Keiichi ; Chandra, Poonam ; Matsuoka, Tomoki ; Ryder, Stuart ; Moriya, Takashi J. ; Kuncarayakti, Hanindyo ; Lee, Shiu-Hang ; Kundu, Esha ; Patnaude, Daniel ; Saito, Tomoki ; Folatelli, Gaston (2021) The Final Months of Massive Star Evolution from the Circumstellar Environment around SN Ic 2020oi The Astrophysical Journal, 918 (1). p. 34. ISSN 0004-637X

[img] PDF
2MB

Official URL: http://doi.org/10.3847/1538-4357/ac0dbc

Related URL: http://dx.doi.org/10.3847/1538-4357/ac0dbc

Abstract

We present the results of Atacama Large Millimeter/submillimeter Array (ALMA) band 3 observations of the nearby type Ic supernova (SN) 2020oi. Under the standard assumptions on the SN-circumstellar medium (CSM) interaction and the synchrotron emission, the data indicate that the CSM structure deviates from a smooth distribution expected from the steady-state mass loss in the very vicinity of the SN (≲1015 cm), which is then connected to the outer smooth distribution (≳1016 cm). This structure is further confirmed through the light-curve modeling of the whole radio data set as combined with the previously reported data at lower frequency. Because this is an explosion of a bare carbon-oxygen (C+O) star with a fast wind, we can trace the mass-loss history of the progenitor of SN 2020oi in the final year. The inferred nonsmooth CSM distribution corresponds to fluctuations on the subyear timescale in the mass-loss history toward the SN explosion. Our finding suggests that the pre-SN activity is likely driven by the accelerated change in the nuclear burning stage in the last moments just before the massive star's demise. The structure of the CSM derived in this study is beyond the applicability of the other methods at optical wavelengths, highlighting the importance and uniqueness of quick follow-up observations of SNe by ALMA and other radio facilities.

Item Type:Article
Source:Copyright of this article belongs to IOP Publishing
Keywords:Supernovae; Circumstellar matter; Radio sources; Millimeter astronomy; Stellar evolution; 1668; 241; 1358; 1061; 1599; Astrophysics - High Energy Astrophysical Phenomena; Astrophysics - Solar and Stellar Astrophysics
ID Code:125594
Deposited On:29 Sep 2022 06:24
Last Modified:29 Sep 2022 06:24

Repository Staff Only: item control page