The companion properties of SNe Ia from the single degenerate model
  Although Type Ia supernovae (SNe Ia) play very important roles in many astrophysical fields, the exact nature of the progenitors of SNe Ia is still unclear. At present, the single degenerate (SD) model is a very likely one. Following the comprehensive SD model developed by Meng & Yang (2010), we show the properties of SNe Ia companions at the moment of the supernova explosion. The results may provide help in searching for companion stars in supernova remnants. We compared our results with the companion candidate Tycho G of Tycho's supernova and found that integral properties of the star (mass, space velocity, radius, luminosity and effective temperature) are all consistent with those predicted from our SD model with the exception of the rotational velocity. If Tycho G was the companion star of Tycho's supernova, an interaction between supernova ejecta and the rotational companion might be a key factor to solve the confliction, and then it could be encouraged to do a detailed numerical simulation about the interaction. 
Xiangcun Meng and Wuming Yang
astro-ph.SR