Type Ia Supernova Explosions in Binary Systems: The Impact on the Secondary Star and Its Consequences

One method of discriminating between the many Type Ia progenitor scenarios isby searching for contaminating hydrogen and helium stripped from the companionstar. We present several high-resolution 2-D numerical simulations of theimpact of a Type Ia supernova explosion with hydrogen-rich main sequence,subgiant, and red giant companions. The binary parameters were chosen torepresent several classes of single-degenerate Type Ia progenitor models thathave been suggested in the literature. We use realistic stellar models andsupernova debris profiles to represent each binary system. For each scenario,we explore the hydrodynamics of the supernova-secondary interaction, calculatethe amount of stellar material stripped from the secondary and the kickdelivered by the impact, and construct the velocity and solid angledistributions of the stripped material. After the impact, the main sequencestar is puffed up, much like a pre-main sequence star. The subgiant companionbehaves similarly. The secondary will not be contaminated by much supernovadebris from the initial impact, but it may accrete low-velocity iron-groupelements (or oxygen and silicon if the ejecta is radially mixed) at late times.A He pre-white dwarf will be left behind after a supernova explosion with a redgiant companion.Comment: 58 text pages, LaTeX, 32 figures (24 BW-postscript plus 8 color-.gif); better versions of the 8 color figures and mpeg movies to be found at ftp://www.astrophysics.arizona.edu/pub/marietta; submitted to Ap