SN 2022crv: IIb, Or Not IIb: That is the Question

Y Dong, S Valenti, C Ashall, M Williamson…�- arXiv preprint arXiv�…, 2023 - arxiv.org
Y Dong, S Valenti, C Ashall, M Williamson, DJ Sand, SD Van Dyk, SW Jha, M Lundquist…
arXiv preprint arXiv:2309.09433, 2023arxiv.org
We present optical and near-infrared observations of SN~ 2022crv, a stripped envelope
supernova in NGC~ 3054, discovered within 12 hrs of explosion by the Distance Less Than
40 Mpc Survey. We suggest SN~ 2022crv is a transitional object on the continuum between
SNe Ib and SNe IIb. A high-velocity hydrogen feature ($\sim $$-$20,000--$-$16,000 $\rm
km\, s^{-1} $) was conspicuous in SN~ 2022crv at early phases, and then quickly
disappeared around maximum light. By comparing with hydrodynamic modeling, we find�…
We present optical and near-infrared observations of SN~2022crv, a stripped envelope supernova in NGC~3054, discovered within 12 hrs of explosion by the Distance Less Than 40 Mpc Survey. We suggest SN~2022crv is a transitional object on the continuum between SNe Ib and SNe IIb. A high-velocity hydrogen feature (20,000 -- 16,000 ) was conspicuous in SN~2022crv at early phases, and then quickly disappeared around maximum light. By comparing with hydrodynamic modeling, we find that a hydrogen envelope of \msun{} can reproduce the behaviour of the hydrogen feature observed in SN~2022crv. The early light curve of SN~2022crv did not show envelope cooling emission, implying that SN~2022crv had a compact progenitor with extremely low amount of hydrogen. The analysis of the nebular spectra shows that SN~2022crv is consistent with the explosion of a He star with a final mass of 4.5 -- 5.6 \msun{} that has evolved from a 16 -- 22 \msun{} zero-age main sequence star in a binary system with about 1.0 -- 1.7 \msun{} of oxygen finally synthesized in the core. The high metallicity at the supernova site indicates that the progenitor experienced a strong stellar wind mass loss. In order to retain a small amount of residual hydrogen at such a high metallicity, the initial orbital separation of the binary system is likely larger than 1000~. The near-infrared spectra of SN~2022crv show a unique absorption feature on the blue side of He I line at 1.005~m. This is the first time that such a feature has been observed in a Type Ib/IIb, and could be due to \ion{Sr}{2}. Further detailed modelling on SN~2022crv can shed light on the progenitor and the origin of the mysterious absorption feature in the near infrared.
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