arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 0911.3774astro-ph.HE
收藏

剥离包层核坍缩超新星核的特征速度

Characteristic velocities of stripped-envelope core-collapse supernova cores

I. Maurer, P. A. Mazzali, J. Deng, A. V. Filippenko, M. Hamuy, R. P. Kirshner, T. Matheson, M. Modjaz, E. Pian, M. Stritzinger, S. Taubenberger, S. Valenti

摘要:

本文通过分析剥离包层核心坍缩超新星(CC-SNe)的星云谱,研究了其内部喷出物的速度。剥离包层CC-SNe是大质量恒星($\geq 8$ M $_{\odot}$)裸核爆炸的结果,它们的晚期光谱通常由强烈的[O { \sc i}] $λλ$ 6300,6363发射线所主导,这些发射线是由最里面的缓慢移动的喷出物产生的,在早期是不可见的,因为它们位于光球之下。的内部喷出物的特征速度获得的样品的56条带包络CC-SNe的不同光谱类型(IIb,Ib,Ic)使用直接测量的线宽以及光谱拟合。对于大多数SNe,该值显示在4500 km s $^{-1}$附近的小分散。对剥离包层CC-SNe的观测($< 100$天)揭示了非常高能SNe的一个亚类,称为宽线SNe(BL-SNe)或高超新星,其特征是早期光谱中的宽吸收线,表明外部喷出物以非常高的速度移动($v \geq 0.1 c$)。在早期阶段被识别为BL的SNe在晚期阶段显示出大的核心速度变化,其中一些具有高得多的速度,而另一些具有与常规CC-SNe相似的速度。这可能表明BL-SNe内部喷出物的非球面性,我们使用合成三维星云光谱调查的可能性。

英文摘要:

The velocity of the inner ejecta of stripped-envelope core-collapse supernovae (CC-SNe) is studied by means of an analysis of their nebular spectra. Stripped-envelope CC-SNe are the result of the explosion of bare cores of massive stars ($\geq 8$ M$_{\odot}$), and their late-time spectra are typically dominated by a strong [O {\sc i}] $λλ$6300, 6363 emission line produced by the innermost, slow-moving ejecta which are not visible at earlier times as they are located below the photosphere. A characteristic velocity of the inner ejecta is obtained for a sample of 56 stripped-envelope CC-SNe of different spectral types (IIb, Ib, Ic) using direct measurements of the line width as well as spectral fitting. For most SNe, this value shows a small scatter around 4500 km s$^{-1}$. Observations ($< 100$ days) of stripped-envelope CC-SNe have revealed a subclass of very energetic SNe, termed broad-lined SNe (BL-SNe) or hypernovae, which are characterised by broad absorption lines in the early-time spectra, indicative of outer ejecta moving at very high velocity ($v \geq 0.1 c$). SNe identified as BL in the early phase show large variations of core velocities at late phases, with some having much higher and some having similar velocities with respect to regular CC-SNe. This might indicate asphericity of the inner ejecta of BL-SNe, a possibility we investigate using synthetic three-dimensional nebular spectra.

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。

↑