发表机构
University of Virginia; National Radio Astronomy Observatory; University of California, Berkeley; Kyoto University; University of California, Santa Cruz; The University of Melbourne; University of Toronto（弗吉尼亚大学; 国家射电天文台; 加州大学伯克利分校; 京都大学; 加州大学圣克鲁兹分校; 墨尔本大学; 多伦多大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究超新星2019yvr前身星质量损失历史，通过射电（GMRT + VLA）和X射线（Swift + Chandra）观测，结合同步加速器自吸收模型等方法，得出质量损失率下降等结果，排除相关CSM密度跃升，为理解前身星提供新认识。
AI 中文摘要
剥离包层超新星（SESNe）大质量恒星前身星的最终生命阶段仍是一个悬而未决的问题，尤其是前身星剥离的时间和程度。观测整个电磁光谱的SESNe能对前身星演化最后阶段的质量损失进行最直接的限制。本文展示了对超新星2019yvr在爆炸后18 - 1784天进行的射电（GMRT + VLA）和X射线（Swift + Chandra）观测。2019yvr是一颗Ib型超新星，在爆炸后约100天转变为IIn型超新星。其射电演化最适合同步加速器自吸收模型，CSM密度分布为$\rho \propto r^{-1.65 \pm 0.25}$，表明爆炸前几年前身星质量损失率在下降。射电得出的激波速度很高，早期超过30000 km/s，暗示前身星致密。联合射电和X射线数据探测到CSM从小于$10^{16}$ cm延伸到约20×$10^{16}$ cm，由约$1 - 3 \times10^{-5} \rm{M_{\odot} yr^{-1}}$的质量损失产生。联合数据集排除了2019yvr中与光学氢发射出现相关的CSM密度的任何急剧跃升。我们将2019yvr与类似的过渡型超新星进行对比，并讨论对前身星的影响。
英文摘要
The final life stages of the massive star progenitors of stripped-envelope supernovae (SESNe) are still an open question, especially when it comes to the timing and magnitude of the progenitor stripping. Observing SESNe across the electromagnetic spectrum allows for the most direct constraints on mass loss in the final stages of progenitor evolution. In this work, we present radio (GMRT+VLA) and X-ray (Swift+Chandra) observations of SN 2019yvr obtained from 18-1786 days post-explosion. SN 2019yvr was a type Ib supernova (SN Ib, with strong helium but little or no hydrogen features) that transitioned into a type IIn supernova (SN IIn, with shock-driven hydrogen features from interaction with circumstellar material (CSM)) at $\sim$ 100 days post-explosion. The radio evolution is best-fit by a synchrotron self-absorbed model with a $ρ\propto r^{-1.54 \pm 0.31}$ CSM density profile, suggesting a decreasing mass-loss rate from the progenitor in the years leading up to the explosion. The radio-derived shock speed is high, more than 30,000 km/s at early times, suggesting a compact progenitor star. The combined radio and X-ray data probe CSM that extends from $1.7 \times 10^{16}$ cm up to $\sim$ 20$\times10^{16}$ cm and was created by mass loss from $\sim (1-6) \times10^{-5} \rm{M_{\odot} yr^{-1}} $ (assuming a CSM speed of 100 km/s). The combined dataset rules out any \emph{dramatic} jump in CSM density (which was seen in the optical analog SN 2014C) associated with the emergence of optical hydrogen emission lines. We place SN 2019yvr in context with similar transitional SNe and discuss implications for the progenitor.
CommentsAccepted to ApJ
