2008/06/19 by S. Bongard, E. Baron, G. Smadja +3 · 3 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Black-body radiation #Flux (metallurgy) #Gamma-ray bursts and supernovae #Ion #Line (geometry) #Materials science #Optics #Optoelectronics #Physics #Radiation #Radiative transfer #Silicon #Spectral line #Supernova #Wavelength #astro-ph
paper · pdf · doi:10.1086/590107
35 pages, 15 figures, ApJ (2008) 684 in press
arxiv created 2008/06/19 · openalex publication_date 2008/10/24 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We use the radiative transfer code PHOENIX to study the line formation of the wavelength region 5000-7000 Å. This is the region where the SN Ia-defining Si II feature occurs. This region is important, since the ratio of the two nearby silicon lines has been shown to correlate with the absolute blue magnitude. We use a grid of LTE synthetic spectral models to investigate the formation of line features in the spectra of SNe Ia. By isolating the main contributors to the spectral formation, we show that the ions that drive the spectral ratio are Fe III, Fe II, Si II, and S II. While the former two strongly dominate the flux transfer, the latter two form in the same physical region inside the supernova. We also show that the naive blackbody that one would derive from a fit to the observed spectrum is very different than the true underlying continuum.