On luminous blue variables as the progenitors of core-collapse supernovae, especially Type IIn supernovae
On luminous blue variables as the progenitors of core-collapse supernovae, especially Type IIn supernovae
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DOI：
10.1111/j.1365-2966.2010.18001.x
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发表时间：
2010-11
影响因子：
4.8
通讯作者：
V. Dwarkadas
中科院分区：
文献类型：
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作者：
V. Dwarkadas
亮蓝变星（LBV）是非常大质量、明亮、不稳定的恒星，经常爆发。在过去的几年里，这些恒星被认为是一些核心坍缩超新星（SNe）的直接祖先，特别是与恒星演化理论相冲突的I型In SNe。在本文中，我们调查了各种方案，其中LBV星已被建议为SNe的直接祖先。这些建议中的许多都源于SNe似乎在高密度介质中膨胀的事实，这被解释为是由具有高质量损失率的风引起的。另一些则是由于感知到SN特性与LBV特性之间的相似性而产生的。只有在SN 2005gl的情况下，我们才发现LBV样祖细胞的有效可能性。其他场景遇到不同程度的困难。指出LBV是直接的核心坍缩SNe祖先的证据远不能令人信服。高质量损失率往往是通过假设风参数推导出来的，这与结果本身相矛盾。高密度并不一定意味着风的质量损失率高：风冲击扫过周围的介质可能会产生一个高密度的外壳，与低相关的风的质量损失率。高密度也可能是由于风团，或由于在SN爆炸为沃尔夫拉叶（WR）星星之前的LBV阶段。一些IIn型SNe似乎更像是SN生命中的一个阶段，而不是一类SNe，并且可能来自不止一种类型的祖先。持续几千年或更短的WR阶段可能是IIn型的更可能的祖先之一，并简要讨论了创建短寿命WR阶段的渠道。
Luminous blue variable (LBV) stars are very massive, luminous, unstable stars that suffer frequent eruptions. In the last few years, these stars have been proposed as the direct progenitors of some core-collapse supernovae (SNe), particularly Type IIn SNe, in conflict with stellar evolution theory. In this paper we investigate various scenarios wherein LBV stars have been suggested as the immediate progenitors of SNe. Many of these suggestions stem from the fact that the SNe appear to be expanding in a high-density medium, which has been interpreted as resulting from a wind with a high mass-loss rate. Others arise due to perceived similarities between the SN characteristics and those of LBVs. Only in the case of SN 2005gl do we find a valid possibility for an LBV-like progenitor. Other scenarios encounter various levels of difficulty. The evidence that points to LBVs as direct core-collapse SNe progenitors is far from convincing. High mass-loss rates are often deduced by making assumptions regarding the wind parameters, which are contradicted by the results themselves. A high density need not necessarily imply a high wind mass-loss rate: wind shocks sweeping up the surrounding medium may give a high-density shell with a low associated wind mass-loss rate. High densities may also arise due to wind clumps, or due to a previous LBV phase before the SN explodes as a WolfRayet (WR) star. Some Type IIn SNe appear to signify more a phase in the life of an SN than a class of SNe, and may arise from more than one type of progenitor. A WR phase that lasts for a few thousand years or less could be one of the more probable progenitors of Type IIns, and channels for creating short-lived WR phases are briefly discussed.