Seven Years of SN 2014C: A Multiwavelength Synthesis of an Extraordinary Supernova
Mar 23, 202233 pages
Published in:
- Astrophys.J. 930 (2022) 1, 57
- Published: May 4, 2022
e-Print:
- 2203.12747 [astro-ph.HE]
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Abstract: (IOP)
SN 2014C was originally classified as a Type Ib supernova, but at phase ϕ = 127 days, post-explosion strong Hα emission was observed. SN 2014C has since been observed in radio, infrared, optical and X-ray bands. Here we present new optical spectroscopic and photometric data spanning ϕ = 947–2494 days post-explosion. We address the evolution of the broadened Hα emission line, as well as broad O iii emission and other lines. We also conduct a parallel analysis of all publicly available multiwavelength data. From our spectra, we find a nearly constant Hα FWHM velocity width of ∼2000 km s that is significantly lower than that of other broadened atomic transitions (∼3000–7000 km s) present in our spectra ( O i λ6300; O iii λ λ4959, 5007; He i λ7065; Ca ii λ λ7291, 7324). The late radio data demand a fast forward shock (∼10,000 km s at ϕ = 1700 days) in rarified matter that contrasts with the modest velocity of the Hα. We propose that the infrared flux originates from a toroidal-like structure of hydrogen surrounding the progenitor system, while later emission at other wavelengths (radio, X-ray) likely originates predominantly from the reverse shock in the ejecta and the forward shock in the quasi-spherical progenitor He-wind. We propose that the Hα emission arises in the boundary layer between the ejecta and torus. We also consider the possible roles of a pulsar and a binary companion.Note:
- 33 pages, 12 figures
References(63)
Figures(14)