SN 2021csp -- the explosion of a stripped envelope star within a H and He-poor circumstellar medium

2021/08/16 by Fraser, Morgan, Stritzinger, Maximilian D., Brennan, Sean J. +48
#Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR)

paper · doi:10.48550/arxiv.2108.07278

Abstract

We present observations of SN 2021csp, a unique supernova (SN) which displays evidence for interaction with H- and He- poor circumstellar material (CSM) at early times. Using high-cadence spectroscopy taken over the first week after explosion, we show that the spectra of SN 2021csp are dominated by C III lines with a velocity of 1800 km s^-1. We associate this emission with CSM lost by the progenitor prior to explosion. Subsequently, the SN displays narrow He lines before metamorphosing into a broad-lined Type Ic SN. We model the bolometric light curve of SN 2021csp, and show that it is consistent with the energetic (4×10⁵¹ erg) explosion of a stripped star, producing 0.4 M_\odot of 56Ni within a ∼1 M_\odot shell of CSM extending out to 400 R_\odot.

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