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arXiv · 0706.0081

Comparative Direct Analysis of Type Ia Supernova Spectra. III. Premaximum

David Branch·M. A. Troxel·David J. Jeffery·Kazuhito Hatano·Miriam Musco·Jerod Parrent·E. Baron·Leann Chau Dang·D. Casebeer·Nicholas Hall·Wesley Ketchum
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Abstract

A comparative study of spectra of 21 Type Ia supernovae (SNe Ia) obtained about one week before maximum light, and 8 spectra obtained 11 or more days before maximum, is presented. To a large extent the premaximum spectra exhibit the defining characteristics of the four groups defined in Paper II (core-normal, broad-line, cool, and shallow-silicon). Comparisons with SYNOW synthetic spectra show that all strong features and most weak ones can be accounted for in a plausible way. The issues of detached high-velocity features, the possible ubiquity of carbon clumps, the maximum detectable ejecta velocities, and the possibility of blueshifted emission-line peaks are discussed.

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David Branch, M. A. Troxel, David J. Jeffery, Kazuhito Hatano, Miriam Musco, Jerod Parrent, E. Baron, Leann Chau Dang, D. Casebeer, Nicholas Hall, Wesley Ketchum. 2007-06-01. Comparative Direct Analysis of Type Ia Supernova Spectra. III. Premaximum. https://doi.org/10.1086/520553

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