Description: The full time-dependent radiation spectrum of a supernova starts when the explosion shock wave reaches the surface of the presupernova envelope. An early radiation spectrum emitted by the expanded and cooling shock-ejected outer layers of an initially compact (R = 10/sup 8/ cm) type I supernova is derived. The relativistically ejected matter is presumably cosmic rays. The Doppler shifted and relativistically time contracted Planck radiation emitted from the expanding surface layers results in an emitted radiation associated with the cooling corresponding to an energy flux of 1.3 x 10/sup 43/ t/sup -1/./sup 05/ ergs sec/sup -1/ with a spectrum I(h..nu..) dh..nu.. = 1.5 x 10/sup 43/ (h..nu..)/sup -0/./sup 92/ ergs eV/sup -1/ and time behavior (h..nu..)/sub eff/ = 108 t/sup -0/./sup 61/ eV. The optical luminosity from the shock is thus low congruent to 10/sup 40/ ergs sec/sup -1/ and 10/sup 43/ ergs total so that it would not be seen as a precursor to the main optical outburst occurring several days later. The x-ray luminosity (several x 10/sup 43/ ergs in milliseconds) is observable but small compared to extended envelope models. The later optical light curve is then interpreted in terms of radioactive heating, ionization and excitation by 0.2 M/sub solar/ of /sup 56/Ni decaying via /sup 56/Co to /sup 56/Fe. Van Hise (1974) has already pointed out that the two optical decay constants are closely given by the respective radioactive decay constants multiplied by 3/4. This is interpreted as requiring efficiency to produce optical radiation, the Fe/sup +/blend, proportional to the (decay rate)/sup 1/3/. It is further noted that when the two optical decay rates are extrapolated to zero time, the intercepts agree with the predicted ratio of deposited energy from /sup 56/Ni ..-->.. /sup 56/Co, and from /sup 56/Co ..-->.. /sup 56/Fe when the appropriate fractional absorption ...
Date: January 1, 1978
Creator: Colgate, S.A. & Petschek, A.
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