Variable thermal energy injection from magnetar spin-down as a possible cause of stripped-envelope supernova light-curve bumps
Variable thermal energy injection from magnetar spin-down as a possible cause of stripped-envelope supernova light-curve bumps
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磁星自旋下降产生的可变热能注入可能是剥离包层超新星光曲线凸起的原因
DOI：
10.1093/mnras/stac1352
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发表时间：
2022
影响因子：
4.8
通讯作者：
Blinnikov, Sergei I.
中科院分区：
文献类型：
--
作者：
Moriya, Takashi J.;Murase, Kohta;Kashiyama, Kazumi;Blinnikov, Sergei I.
一些剥层超新星如I型超亮超新星的光度演化很难用经典的56 Ni核衰变加热来解释。一个流行的替代热源是快速自旋的强磁化快速旋转中子星（磁星）。最近的观测表明，I型超亮超新星的光变曲线通常是凹凸不平的，有多个光度峰值。光变曲线不平坦的原因尚不清楚。在这项研究中，我们调查的可能性，光变曲线的隆起所造成的变化的热能注入从磁星自旋下降。我们发现，在热能注入的时间增加，可以导致多个光度峰。由可变的热能注入引起的多个光度峰被发现伴随着光球温度的显着增加，而光球半径没有显着变化。我们表明，通过暂时将磁星自旋向下能量输入增加2-3倍持续5-20天，可以再现SN 2015 bn和SN 2019 stc的凹凸光变曲线。然而，并不是所有的光变曲线颠簸都伴随着我们的合成模型所预测的光球温度的明显增加。特别是，SN 2019 stc的二次光变曲线凸起伴随着光球半径的时间增加，而不是温度，这在我们的合成模型中没有看到。因此，我们的结论是，并不是所有的光变曲线凸点观察到的发光超新星是由可变的热能注入磁星自旋下降和一些凸点可能是由不同的机制。
Luminosity evolution of some stripped-envelope supernovae such as Type I superluminous supernovae is difficult to explain by the canonical56Ni nuclear decay heating. A popular alternative heating source is rapid spin-down of strongly magnetized rapidly rotating neutron stars (magnetars). Recent observations have indicated that Type I superluminous supernovae often have bumpy light curves with multiple luminosity peaks. The cause of bumpy light curves is unknown. In this study, we investigate the possibility that the light-curve bumps are caused by variations of the thermal energy injection from magnetar spin-down. We find that a temporal increase in the thermal energy injection can lead to multiple luminosity peaks. The multiple luminosity peaks caused by the variable thermal energy injection is found to be accompanied by significant increase in photospheric temperature, and photospheric radii are not significantly changed. We show that the bumpy light curves of SN 2015bn and SN 2019stc can be reproduced by temporarily increasing magnetar spin-down energy input by a factor of 2–3 for 5–20 d. However, not all the light-curve bumps are accompanied by the clear photospheric temperature increase as predicted by our synthetic models. In particular, the secondary light-curve bump of SN 2019stc is accompanied by a temporal increase in photospheric radii rather than temperature, which is not seen in our synthetic models. We therefore conclude that not all the light-curve bumps observed in luminous supernovae are caused by the variable thermal energy injection from magnetar spin-down and some bumps are likely caused by a different mechanism.