skip to main content

SciTech ConnectSciTech Connect

Title: Signatures of a companion star in type Ia supernovae

Although type Ia supernovae (SNe Ia) have been used as precise cosmological distance indicators, their progenitor systems remain unresolved. One of the key questions is whether there is a nondegenerate companion star at the time of a thermonuclear explosion of a white dwarf. In this paper, we investigate whether an interaction between the SN ejecta and the companion star may result in observable footprints around the maximum brightness and thereafter, by performing multidimensional radiation transfer simulations based on hydrodynamic simulations of the interaction. We find that such systems result in variations in various observational characteristics due to different viewing directions, and the predicted behaviors (redder and fainter for the companion direction) are the opposite of what were suggested by the previous study. The variations are generally modest and within observed scatters. However, the model predicts trends between some observables different from those observationally derived, so a large sample of SNe Ia with small calibration errors may be used to constrain the existence of such a companion star. The variations in different colors in optical band passes can be mimicked by external extinctions, so such an effect could be a source of scatter in the peak luminosity and derived distance. Aftermore » the peak, hydrogen-rich materials expelled from the companion will manifest themselves in hydrogen lines, but Hα is extremely difficult to identify. Alternatively, we find that P{sub β} in postmaximum near-infrared spectra can potentially provide a powerful diagnostic.« less
Authors:
 [1] ; ;  [2]
  1. Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan)
  2. Research Center for the Early Universe, School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)
Publication Date:
OSTI Identifier:
22370501
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 794; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BRIGHTNESS; CALIBRATION; COLOR; HYDROGEN; INFRARED SPECTRA; INTERACTIONS; LUMINOSITY; RADIANT HEAT TRANSFER; SIMULATION; THERMONUCLEAR EXPLOSIONS; TYPE I SUPERNOVAE; WHITE DWARF STARS