Comparative Direct Analysis of Type Ia Supernova Spectra. II. Maximum Light
Abstract
A comparative study of near-maximum-light optical spectra of 24 Type Ia supernovae (SNe Ia) is presented. The spectra are assigned to four groups. Seven ``core-normal'' SNe Ia have very similar spectra, except for strong, high-velocity Ca II absorption in SN 2001el. Seven SNe Ia are assigned to a ``broad-line'' group, the most extreme of which is SN 1984A. Five SNe Ia, including SN 1991bg, are assigned to a ``cool'' group. Five SNe Ia, including SN 1991T, are assigned to a ``shallow-silicon'' group. Comparisons with SYNOW synthetic spectra provide a basis for discussion of line identifications and an internally consistent quantification of the maximum-light spectroscopic diversity among SNe Ia. The extent to which SN Ia maximum-light spectra appear to have a continuous distribution of properties, rather than consist of discrete subtypes, is discussed.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- April 2006
- DOI:
- 10.1086/502778
- arXiv:
- arXiv:astro-ph/0601048
- Bibcode:
- 2006PASP..118..560B
- Keywords:
-
- Stars: Supernovae: General;
- Astrophysics
- E-Print:
- 38 pages including 14 figures and 5 tables, submitted to PASP