Constraining Massive Star Activities in the Final Years through Properties of Supernovae and Their Progenitors
Constraining Massive Star Activities in the Final Years through Properties of Supernovae and Their Progenitors
复制标题
DOI：
10.3847/1538-4357/ab1a37
复制
发表时间：
2019-04
期刊：
影响因子：
--
通讯作者：
R. Ouchi;K. Maeda
中科院分区：
文献类型：
--
作者：
R. Ouchi;K. Maeda
最近对爆炸后超新星（SNe）的观测表明，很大一部分超新星在附近具有受限星周物质（CSM），并且超新星爆发前增强的质量损失可能是一个共同特性。这种现象的物理机制仍不清楚，并且能量沉积到外壳中被认为是受限 CSM 的可能原因。在这项工作中，我们计算了从核心塌陷前几年开始包络层对各种类型持续能量沉积的响应。我们进一步研究了由此产生的前身结构将如何影响随后发生的超新星的出现。虽然人们怀疑超爱丁顿能量沉积可能会导致强烈的和/或喷发的质量损失，以解释受限的CSM，但我们发现，注入包层的高度超爱丁顿能量极大地改变了祖星的结构，并且由此产生的超新星的特性变得与典型的超新星不一致。这一论点限制了最后几年可能的恒星活动所涉及的能量预算最多比爱丁顿光度高一个数量级。然而，这种能源生产不会在几年的时间尺度内动态地产生强风。因此，我们提出，由亚爱丁顿能量注入引起的适度包络膨胀引发的次级效应（例如，脉动或二元相互作用）可能会引起质量损失。
Recent observations of supernovae (SNe) just after the explosion suggest that a good fraction of SNe have the confined circumstellar material (CSM) in the vicinity, and the pre-SN enhanced mass loss may be a common property. The physical mechanism of this phenomenon is still unclarified, and the energy deposition into the envelope has been proposed as a possible cause of the confined CSM. In this work, we have calculated the response of the envelope to various types of sustained energy deposition starting from a few years before the core collapse. We have further investigated how the resulting progenitor structure would affect the appearance of the ensuing supernova. While it has been suspected that a super-Eddington energy deposition may lead to a strong and/or eruptive mass loss to account for the confined CSM, we have found that a highly super-Eddington energy injection into the envelope changes the structure of the progenitor star substantially, and the properties of the resulting SNe become inconsistent with typical SNe. This argument constrains the energy budget involved in the possible stellar activity in the final years to be at most one order of magnitude higher than the Eddington luminosity. Such an energy generation, however, would not dynamically develop a strong wind on a timescale of a few years. We therefore propose that a secondary effect (e.g., pulsation or binary interaction) triggered by moderate envelope inflation, which is caused by sub-Eddington energy injection, likely induces the mass loss.