Comparison between the first and second mass eruptions from progenitors of Type IIn supernovae
Comparison between the first and second mass eruptions from progenitors of Type IIn supernovae
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DOI：
10.1051/0004-6361/202038637
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发表时间：
2020-06
影响因子：
6.5
通讯作者：
Naoto Kuriyama;T. Shigeyama
中科院分区：
文献类型：
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作者：
Naoto Kuriyama;T. Shigeyama
上下文一些大质量恒星会经历偶发性的强烈质量损失阶段，伴随着光度的波动。喷出的物质在星星周围形成星周物质，随后的核心坍缩导致了IIn型超新星，其特征是超新星喷出物和星周物质之间的相互作用。引发这些大规模爆发的能量来源和外流的动力学尚未得到明确解释。此外，如果这些事件重复发生，大规模喷发本身可以改变包层的密度结构，并影响随后的大规模喷发的动力学。大量的观测证据表明，在核心坍塌之前，有多次大规模喷发。目标。我们调查的第一次大规模喷发和随后的第二次大规模喷发事件相比，第一次事件的性质改变的信封的密度结构。方法.我们在15颗M型恒星的氢包层底部放置了两次额外的能量，并用辐射流体动力学模拟程序计算了它们的时间演化。我们没有讨论能量来源的起源，而是集中在一颗大质量星星重复爆发的动力学上。结果第一次和第二次大规模爆发在光度、颜色和产生的星周物质的数量方面有显着差异。第二次爆发导致了一个更红的爆发事件，其中相关的增亮阶段持续的时间比第一次更长。在第一次和第二次事件中，即使沉积的能量相同，喷出的物质数量也不同，但差异取决于星星的密度结构。结论.即将到来的高节奏和深瞬变调查将为我们提供大量的超新星前活动，其中一些可能会显示多峰光变曲线。这些应解释为考虑到密度结构的影响，改变了以前的突出事件。
Context. Some massive stars experience episodic and intense mass loss phases with fluctuations in the luminosity. Ejected material forms circumstellar matter around the star, and the subsequent core collapse results in a Type IIn supernova that is characterized by interaction between supernova ejecta and circumstellar matter. The energy source that triggers these mass eruptions and dynamics of the outflow have not been clearly explained. Moreover, the mass eruption itself can alter the density structure of the envelope and affect the dynamics of the subsequent mass eruption if these events are repeated. A large amount of observational evidence suggests multiple mass eruptions prior to core collapse. Aims. We investigate the density structure of the envelope altered by the first mass eruption and the nature of the subsequent second mass eruption event in comparison with the first event. Methods. We deposited extra energy at the bottom of the hydrogen envelope of 15 M⊙ stars twice and calculated the time evolution by radiation hydrodynamical simulation code. We did not deal with the origin of the energy source, but focused on the dynamics of repeated mass eruptions from a single massive star. Results. There are significant differences between the first and second mass eruptions in terms of the luminosity, color, and amount of produced circumstellar matter. The second eruption leads to a redder burst event in which the associated brightening phase lasts longer than the first. The amount of ejected matter is different even with the same deposited energy in the first and second event, but the difference depends on the density structure of the star. Conclusions. Upcoming high cadence and deep transient surveys will provide us a lot of pre-supernova activities, and some of which might show multi-peaked light curves. These should be interpreted taking the effect of density structure altered by the preceding outburst events into consideration.