Spectral Modeling of SNe Ia Near Maximum Light: Probing the Characteristics of Hydro Models

We have performed detailed NLTE spectral synthesis modeling of 2 types of 1D hydro models: the very highly parameterized deflagration model W7, and two delayed detonation models. We find that overall both models do about equally well at fitting well observed SNe Ia near to maximum light. However, the Si II 6150 feature of W7 is systematically too fast, whereas for the delayed detonation models it is also somewhat too fast, but significantly better than that of W7. We find that a parameterized mixed model does the best job of reproducing the Si II 6150 line near maximum light and we study the differences in the models that lead to better fits to normal SNe Ia. We discuss what is required of a hydro model to fit the spectra of observed SNe Ia near maximum light. Subject headings: stars: atmospheres — supernovae: SN 1992A, SN 1994D, SN 1999ee Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks, Rm. 100, Norman, OK 73019-2061, USA Computational Research Division, Lawrence Berkeley National Laboratory, MS 50F-1650, 1 Cyclotron Rd, Berkeley, CA 94720-8139 USA Institute de Physique Nucléaire Lyon, Bâtiment Paul Dirac Université Claude Bernard Lyon-1 Domaine scientifique de la Doua 4, rue Enrico Fermi 69622 Villeurbanne cedex, France Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany