A source of late time emission from type II supernovae - Radioactivity shock heating?
Abstract
A simple model for late time (t greater than about 100 days) H-alpha emission from a type II supernova due to radioactive decay of Co-56 - Fe-56 is used to analyze the evolution of the flux behavior in six supernovae. Three (79C, 80K and 87F) show a substantially higher (by an order of magnitude) H-alpha flux than that predicted by the radioactive model. The most probable reason for this is the shock heating of the envelope of the supernova as it interacts with the surrounding pre-SN wind. In two of these (79C and 87F) the effects of shock heating are especially large and appear already in the first year. They also have other distinctive characteristics related to the presence of a dense wind: (1) a wider H-alpha emission; (2) a narrow H-alpha emission component around the light maximum; (3) an absence of H-alpha absorption. SN 1987F had probably the highest wind density parameter. Observation of the evolution of the late time H-alpha flux in a type II supernova could be an effective method of studying mass loss in pre-SN at the final stage of evolution, about 1000 years before explosion.
- Publication:
-
Pisma v Astronomicheskii Zhurnal
- Pub Date:
- December 1990
- Bibcode:
- 1990PAZh...16.1066C
- Keywords:
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- H Alpha Line;
- Radioactive Decay;
- Shock Heating;
- Supernovae;
- Cobalt Isotopes;
- Iron Isotopes;
- Stellar Evolution;
- Astrophysics