期刊
ASTROPHYSICAL JOURNAL
卷 623, 期 2, 页码 1011-1016出版社
UNIV CHICAGO PRESS
DOI: 10.1086/428608
关键词
supernovae : general
The photometric and spectroscopic properties of 26 well-observed Type Ia Supernovae (SNe Ia) were analyzed with the aim of exploring SN Ia diversity. The sample includes ( Branch) normal SNe, as well as extreme events such as SN 1991T and SN 1991bg, while the truly peculiar SNe Ia, SN 2000cx and SN 2002cx, are not included in our sample. A statistical treatment reveals the existence of three different groups. The first group ( FAINT) consists of faint SNe Ia similar to SN 1991bg, with low expansion velocities and rapid evolution of Si II velocity. A second group consists of normal SNe Ia, also with high temporal velocity gradient ( HVG), but with brighter mean absolute magnitude [M-B] = -19.3 and higher expansion velocities than the FAINT SNe. The third group includes both normal and SN 1991T-like SNe Ia: these SNe populate a narrow strip in the Si II velocity evolution plot, with a low-velocity gradient (LVG), but have absolute magnitudes similar to HVGs. While the FAINT and HVG SNe Ia together seem to define a relation between R( Si II) and Delta m(15)(B), the LVG SNe either do not conform to that relation or define a new, looser one. The R( Si II) premaximum evolution of HVGs is strikingly different from that of LVGs. We discuss the impact of this evidence on the understanding of SN Ia diversity, in terms of explosion mechanisms, degree of ejecta mixing, and ejecta - circumstellar material interaction.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据