Spectral Dataset of Stripped-Envelope Supernovae from the Tsinghua Supernova Group
Abstract
The extent of envelope stripping in the progenitor stars is directly reflected in the diversity of spectral features observed in stripped-envelope supernovae (SESNe). Through extensive spectral observation and analysis, we aim to clarify the statistical differences between the subclasses of SESNe. The Tsinghua Supernova group obtained 249 optical spectra of 62 SESNe during the years from 2010 to 2020, covering phases from 16 to over 190 days relative to maximum light. Most spectra were obtained during the photospheric phases after the supernova explosion. For each spectrum, the pseudo-equivalent widths (pEWs) and blueshift velocities of principal lines were measured. We further investigated the common spectral features by analysing their velocity and strength correlations across all subtypes. We identify the feature near 6200~\AA\ in SNe Ib as H through comparison with SNe IIb and Ic, which resolves inconsistent literature interpretations. Our finding reveals prevalent residual hydrogen in SNe Ib, further supporting a continuous stripping sequence from SNe IIb to Ib. We observe a trend in increasing velocity among different subtypes of stripped-envelope SNe, with SNe IIb exhibiting the lowest line velocities, followed by Ib, Ic, and Ic-BL. Typically, the O~I lines in SNe Ic/Ic-BL are stronger than those seen in SNe IIb/Ib. In nebular phases, the [Ca II] emission dominates over [O I] in SNe IIb/Ib while [O I] is stronger in SNe Ic, including the He-rich SN 2016coi. This spectral dichotomy implies that progenitors of SNe Ic (BL) have more massive CO cores and hence higher initial masses.
Cite
@article{arxiv.2603.12604,
title = {Spectral Dataset of Stripped-Envelope Supernovae from the Tsinghua Supernova Group},
author = {Danfeng Xiang and Xiaofeng Wang and Jujia Zhang and Shengyu Yan and Han Lin and Liming Rui and Jun Mo and Xinghan Zhang and Hanna Sai and Cheng Miao and Gaobo Xi and Zhihao Chen and Fangzhou Guo and Xiaoran Ma and Gaici Li and Tianmeng Zhang and Liyang Chen and Jialian Liu and Wenxiong Li and Xulin Zhao and Fang Huang and Yongzhi Cai and Weili Lin and Jie Lin and Chengyuan Wu and Maokai Hu and Cuiying Song and Jicheng Zhang and Qiqi Xia and Zhitong Li and Linyi Li and Kaicheng Zhang and Qian Zhai and Juncheng Chen and Zhou Fan and Jianning Fu and Shengbang Qian and Hong Wu and Xue-Bing Wu and Huawei Zhang and Junbo Zhang and Liyun Zhang and Jie Zheng},
journal= {arXiv preprint arXiv:2603.12604},
year = {2026}
}
Comments
Accepted for publication in A&A