Stripped envelope supernovae are a sub-class of core collapse supernovae showing several stages of H/He shell stripping that determines the class: H-free/He-poor SNe are classified as Type Ic, H-poor/He-rich are Type Ib, and H/He-rich are Type IIb. Stripping H/He with only stellar wind requires significantly higher mass loss rates than observed while binary-involved mass transfer may usually not strip enough to produce H/He free SNe. Type Ib/c SNe are sometimes found to include weak H/He transient lines as a product of a trace amount of H/He left over from stripping processes. The extent and mass of the H/He required to produce these lines is not well known. In this work, a 22 M⊙ progenitor model is stripped of the H/He shells in five steps prior to collapse and then exploded at four explosion energies. Requiring both optical and NIR He I lines for helium identification does not allow much He mass to be hidden in SE--SNE. Increasing the mass of He above the CO core delays the visibility of O I 7774 in early spectra. Our SN Ib-like models are capable of reproducing the spectral evolution of a set of observed SNe with reasonable estimated Ek accuracy. Our SN\,IIb-like models can partially reproduce low energy observed SN IIb, but we find no observed comparison for the SN IIb-like models with high Ek.
@article{arxiv.2008.07887,
title = {How much H and He is "hidden" in SNe Ib/c? -- II. Intermediate-mass objects: a 22 M$_{\odot}$ progenitor case study},
author = {Jacob Teffs and Thomas Ertl and Paolo Mazzali and Stephan Hachinger and H. -Thomas Janka},
journal= {arXiv preprint arXiv:2008.07887},
year = {2020}
}
Comments
19 pages, 15 figures. Accepted by MNRAS, awaiting publication