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Session 97 - Supernovae.
Oral session, Wednesday, January 17
Salon del Rey Central, Hilton
Results of numerical calculations of Type II supernova light curves are presented. The model progenitor stars have 6 M_ødot cores and various envelopes. Five parameters that affect the light curves are examined: the ejected mass, the progenitor radius, the explosion energy, the ^56Ni mass, and the extent of ^56Ni mixing. The following effects have been found: 1) the larger the progenitor radius the brighter the early--time light curve, with little effect on the late--time light curve, 2) the larger the envelope mass the fainter the early light curve and the flatter the slope of the late light curve, 3) the larger the explosion energy the brighter the early light curve and the steeper the slope of the late light curve, 4) the larger the ^56Ni mass the brighter the overall light curve after 20 to 50 days, with no effect on the early light curve, 5) the more extensive the ^56Ni mixing the brighter the early light curve and the steeper the late light curve. The primary parameters effecting the light curve shape are the progenitor radius and the ejected mass. The secondary parameters are the expolosion energy, ^56Ni mass and ^56Ni mixing. We find that while in principle the general shape and absolute magnitude of a light curve indicate a unique set of parameters, in practice it is difficult to avoid some ambiguity in the parameters. We find that the nickel--powered diffusion wave and the recombination of helium produce a prominant secondary peak in all our calculations. The feature is less prominent when compositional mixing, both ^56Ni mixing and mixing between the hydrogen and helium layers, occurs. The model photospheric temperatures and velocities are presented, for comparison to observation.
Program listing for Wednesday