PI: Bradley E. Schaefer, Louisiana State University, firstname.lastname@example.org
Address: Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA
CoI: Ashley Pagnotta, Louisiana State University
Title: Solving the Type Ia Supernova Progenitor Problem By Identifying the Ex- Companion Stars in Three LMC Supernova Remnants of Confident Type Ia Events
Abstract: We propose to examine the centers of three LMC supernova remnants (that are known to be from Type Ia supernovae due to the spectra of their light echoes) for ex-companion stars of the progenitor. The various progenitor possibilities all leave behind distinct ex-companion stars: recurrent novae leave behind red giants and subgiants, symbiotic stars leave behind only large red giants, supersoft sources leave behind subgiants or fairly massive main sequence stars, while double-degenerate systems leave behind no ex-companion. Any ex-companion in the LMC must be brighter than V=24 and lie within a few arc-seconds of the geometric center of the remnant, and the star density will have only few stars in the error ellipse. We will recognize the ex-companions by their high radial velocity, blue-shifted wings on the iron lines, or high rotational velocity. The Type Ia progenitor problem has been identified as one of the most important questions in current astrophysics by the Decadal Review, and we propose a practical way to solve the problem for three specific Ia supernovae.
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