Title:
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Supernova Progenitor Constraints from Circumstellar Interaction: Type Ia 
(Stockholm Observatory preprint No. 86)


Authors:
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Peter Lundqvist  &  Robert J. Cumming   (Stockholm Observatory)


Abstract:
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Searching for the presence of a circumstellar medium (CSM) is a direct 
observational way to discriminate between different types of progenitor 
systems for Type Ia supernovae (SNe Ia). We have modeled whether such gas
may give rise to detectable emission, especially in H-alpha, and compare 
the models with observations of SN 1994D. We obtain a mass loss rate less 
than about 2.5E{-5} solar masses per year for a wind speed of 10 km s^{-1}.
We find that X-ray observations in the range 5-10 keV, e.g., with AXAF, 
provide the most useful limits on the mass loss, while high-resolution 
optical spectroscopy offers the only direct way of identifying circumstellar 
hydrogen.


To appear in:
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Advances in Stellar Evolution, ed. R.T. Rood & A. Renzini (Cambridge Univeristy
Press)