Comparative Direct Analysis of Type Ia Supernova Spectra. III. Premaximum
Astrophysics
2009-11-13 v1
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.
Keywords
Cite
@article{arxiv.0706.0081,
title = {Comparative Direct Analysis of Type Ia Supernova Spectra. III. Premaximum},
author = {David Branch and M. A. Troxel and David J. Jeffery and Kazuhito Hatano and Miriam Musco and Jerod Parrent and E. Baron and Leann Chau Dang and D. Casebeer and Nicholas Hall and Wesley Ketchum},
journal= {arXiv preprint arXiv:0706.0081},
year = {2009}
}
Comments
Accepted by PASP. 38 pages