We present the complete sample of stripped-envelope supernova (SN) spectra observed by the Lick Observatory Supernova Search (LOSS) collaboration over the last three decades: 888 spectra of 302 SNe, 652 published here for the first time, with 384 spectra (of 92 SNe) having photometrically-determined phases. After correcting for redshift and Milky Way dust reddening and reevaluating the spectroscopic classifications for each SN, we construct mean spectra of the three major spectral subtypes (Types IIb, Ib, and Ic) binned by phase. We compare measures of line strengths and widths made from this sample to the results of previous efforts, confirming that O I {\lambda}7774 absorption is stronger and found at higher velocity in Type Ic SNe than in Types Ib or IIb SNe in the first 30 days after peak brightness, though the widths of nebular emission lines are consistent across subtypes. We also highlight newly available observations for a few rare subpopulations of interest.
@article{arxiv.1810.03650,
title = {The Berkeley Sample of Stripped-Envelope Supernovae},
author = {Isaac Shivvers and Alexei V. Filippenko and Jeffrey M. Silverman and WeiKang Zheng and Ryan J. Foley and Ryan Chornock and Aaron J. Barth and S. Bradley Cenko and Kelsey I. Clubb and Ori D. Fox and Mohan Ganeshalingam and Melissa L. Graham and Patrick L. Kelly and Io K. W. Kleiser and Douglas C. Leonard and Weidong Li and Thomas Matheson and Jon C. Mauerhan and Maryam Modjaz and Franklin J. D. Serduke and Joseph C. Shields and Thea N. Steele and Brandon J. Swift and Diane S. Wong and Heechan Yuk},
journal= {arXiv preprint arXiv:1810.03650},
year = {2018}
}
Comments
13 pages; 14 figures; 3 tables. Accepted for publication in MNRAS