2020/08/23 by Rachel J. Bruch, Avishay Gal-Yam, Steve Schulze +46
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Cosmic Phenomena #Emission spectrum #Flash (photography) #Gamma-ray bursts and supernovae #Stars #Stellar evolution #Supernova #Transient (computer programming) #Type II supernova #Variable star #astro-ph.HE
paper · pdf · doi:10.3847/1538-4357/abef05
arxiv created 2020/08/23 · openalex created_date 2020/09/01 · openalex publication_date 2021/05/01 · arxiv updated 2021/05/12 · openalex updated_date 2026/08/05
Abstract Spectroscopic detection of narrow emission lines traces the presence of circumstellar mass distributions around massive stars exploding as core-collapse supernovae. Transient emission lines disappearing shortly after the supernova explosion suggest that the material spatial extent is compact and implies an increased mass loss shortly prior to explosion. Here, we present a systematic survey for such transient emission lines (Flash Spectroscopy) among Type II supernovae detected in the first year of the Zwicky Transient Facility survey. We find that at least six out of ten events for which a spectrum was obtained within two days of the estimated explosion time show evidence for such transient flash lines. Our measured flash event fraction (>30% at 95% confidence level) indicates that elevated mass loss is a common process occurring in massive stars that are about to explode as supernovae.