Self-Shielding Of Soft X-Rays In Type Ia Supernova Progenitors

There are insufficient super-soft (similar to 0.1 keV) X-ray sources in either spiral or elliptical galaxies to account for the rate of explosion of Type Ia supernovae (SNe Ia) in either the single-degenerate or the double-degenerate scenarios. We quantify the amount of circumstellar matter that would be required to suppress the soft X-ray flux by yielding a column density in excess of 10(23) cm(-2). We summarize evidence that appropriate quantities of matter are extant in SNe Ia and in recurrent novae that may be supernova precursors. The obscuring matter is likely to have a large, but not complete, covering factor and to be substantially non-spherically symmetric. Assuming that much of the absorbed X-ray flux is re-radiated as blackbody radiation in the UV, we estimate that less than or similar to 100 sources might be detectable in the Galaxy Evolution Explorer All-sky Survey.NSF AST-1109801Astronom