1. iPTF14hls in the Circumstellar Medium Interaction Model: A Promising Candidate for a Pulsational Pair-instability Supernova.
- Author
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Wang, Ling-Jun, Liu, Liang-Duan, Lin, Wei-Li, Wang, Xiao-Feng, Dai, Zi-Gao, Li, Bing, and Song, Li-Ming
- Subjects
TYPE II supernovae ,LIGHT curves ,SUPERNOVAE ,STELLAR winds ,CIRCUMSTELLAR matter ,WIND speed - Abstract
iPTF14hls is a luminous Type II supernova (SN) with a bumpy light curve whose origin remains under debate. It maintains a roughly constant effective temperature and luminosity for about 600 days after discovery, followed by a slow decay. About âĽ1000 days after discovery, the light curve transitions to a very steep decline. A spectrum taken during this steep-decline phase shows clear signatures of a shock interaction with a dense circumstellar medium (CSM). Here, we explore the possibility of iPTF14hls as an interaction-powered SN. The light curve of iPTF14hls can be fitted with wind-like CSMs. Analytic modeling indicates that iPTF14hls may have undertaken six episodes of mass loss during the last âĽ200 yr. Assuming that the 1954 eruption triggered the last mass-loss episode, the stellar wind velocity is determined to be 40â'70 km s
â'1 , depending on different models. Mass-loss rates are in the range 0.4â€"3.3 M⊙ yrâ'1 . The inferred total mass of the ejecta and CSMs (Mej + MCSMs ≠245 M⊙ ) supports the idea that iPTF14hls may be a candidate for a (pulsational) pair-instability SN. Discoveries and observations of similar stellar explosions will help us to understand these peculiar SNe. [ABSTRACT FROM AUTHOR]- Published
- 2022
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