由于星周相互作用和神秘的超新星SN 2018gep引起的快速蓝色光学瞬变
Fast Blue Optical Transients due to Circumstellar Interaction and the Mysterious Supernova SN 2018gep
摘要：
SN 2018gep（ZTF 18abukavn）的发现挑战了我们对大质量恒星及其超新星（SNe）晚期演化的理解。这个SN（光谱分类为宽线Ic型SN）的光度快速上升，表明喷出物与致密的星周介质（CSM）相互作用，而需要额外的能量源，如$^{56}$ Ni衰变来解释后期的光变曲线。这些特征暗示了一颗大质量恒星的爆炸，伴随着超新星前的质量损失。在这项工作中，我们研究了像SN 2018gep这样快速演变的天体物理瞬变的物理起源。我们调查波驱动的质量损失机制，以及它如何依赖于模型参数，如祖质量和沉积能量，寻找恒星祖模型，可以重现观测数据。一个模型的喷出物质量$\sim \! 2 \, M_{\odot}$，爆炸能量$\sim \! 10^{52}$ erg，一个拱星介质的质量$\sim \! 0.3 \, M_{\odot}$和半径$\sim \! 1000 \, R_{\odot}$，和一个$^{56}$镍质量$\sim \! 0.3 \, M_{\odot}$提供了一个很好的拟合热光变曲线。我们还研究了相互作用动力的光变曲线如何更普遍地依赖于这些参数，以及喷出物的速度如何有助于打破简并。我们发现，波驱动的质量损失和通过脉动对不稳定性的质量喷射都可以在SN 2018gep中产生致密的CSM，但我们倾向于后者的可能性。
英文摘要：
The discovery of SN 2018gep (ZTF18abukavn) challenged our understanding of the late-phase evolution of massive stars and their supernovae (SNe). The fast rise in luminosity of this SN (spectroscopically classified as a broad-lined Type Ic SN), indicates that the ejecta interacts with a dense circumstellar medium (CSM), while an additional energy source such as $^{56}$Ni-decay is required to explain the late-time light curve. These features hint at the explosion of a massive star with pre-supernova mass-loss. In this work, we examine the physical origins of rapidly evolving astrophysical transients like SN 2018gep. We investigate the wave-driven mass-loss mechanism and how it depends on model parameters such as progenitor mass and deposition energy, searching for stellar progenitor models that can reproduce the observational data. A model with an ejecta mass $\sim \! 2 \, M_{\odot}$, explosion energy $\sim \! 10^{52}$ erg, a circumstellar medium of mass $\sim \! 0.3 \, M_{\odot}$ and radius $\sim \! 1000 \, R_{\odot}$, and a $^{56}$Ni mass of $\sim \! 0.3 \, M_{\odot}$ provides a good fit to the bolometric light curve. We also examine how interaction-powered light curves depend more generally on these parameters, and how ejecta velocities can help break degeneracies. We find both wave-driven mass-loss and mass ejection via pulsational pair-instability can plausibly create the dense CSM in SN 2018gep, but we favor the latter possibility.
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。
