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arXiv 1807.07576astro-ph.HE
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红与蓝:热核超新星的早期观测揭示了两个不同的群体?

Red vs Blue: Early observations of thermonuclear supernovae reveal two distinct populations?

Maximilian D. Stritzinger, Benjamin J. Shappee, Anthony L. Piro, Christopher Ashall, E. Baron, Peter Hoeflich, Simon Holmbo, Thomas W. -S. Holoien, M. M. Philli… 展开作者

Maximilian D. Stritzinger, Benjamin J. Shappee, Anthony L. Piro, Christopher Ashall, E. Baron, Peter Hoeflich, Simon Holmbo, Thomas W. -S. Holoien, M. M. Phillips, C. R. Burns, Carlos Contreras, Nidia Morrell, Michael A. Tucker

摘要:

我们研究了十几个Ia型超新星的早期阶段内在$(B-V)_{0}$颜色演化的推断时间的第一光($t_{first}$)的三天内发现,并有$(B-V)_0$颜色信息开始在5天内的$t_{first}$。样本表明有两个不同的早期种群。第一种是蓝色的种群,进化缓慢,第二种是红色的种群,进化更快。我们发现,早期的蓝色事件都是1991 T/1999 aa的类似与更明亮的缓慢下降的光变曲线比那些表现出早期的红色。将第一个示例放置在分支图上(即,\ion{Si}{2} $λλ$ 5972,6355伪等效宽度的比率)指示所有蓝色物体都是分支浅硅(SS)光谱类型,而除了类似2000 Cx的SN~ 2012 fr之外,所有早期红色事件都是分支核正常(CN)或CooL(CL)类型。一些潜在的过程有助于早期排放的探索,我们发现,在一般情况下,在同伴碰撞模型中固有的视角依赖性是不一致的所有SS对象与早期的观测是蓝色的,表现出过剩。我们警告说,在解释早期相位光变曲线时必须非常小心,因为可能有各种物理过程可能在起作用,而且重要的理论工作仍有待完成。

英文摘要:

We examine the early phase intrinsic $(B-V)_{0}$ color evolution of a dozen Type~Ia supernovae discovered within three days of the inferred time of first light ($t_{first}$) and have $(B-V)_0$ color information beginning within 5 days of $t_{first}$. The sample indicates there are two distinct early populations. The first is a population exhibiting blue colors that slowlybevolve, and the second population exhibits red colors and evolves more rapidly. We find that the early-blue events are all 1991T/1999aa-like with more luminous slower declining light curves than those exhibiting early-red colors. Placing the first sample on the Branch diagram (i.e., ratio of \ion{Si}{2} $λλ$5972, 6355 pseudo-Equivalent widths) indicates all blue objects are of the Branch Shallow Silicon (SS) spectral type, while all early-red events except for the 2000cx-like SN~2012fr are of the Branch Core-Normal (CN) or CooL (CL) type. A number of potential processes contributing to the early emission are explored, and we find that, in general, the viewing-angle dependance inherent in the companion collision model is inconsistent with all SS objects with early-time observations being blue and exhibiting an excess. We caution that great care must be taken when interpreting early-phase light curves as there may be a variety of physical processes that are possibly at play and significant theoretical work remains to be done.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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