Tidal disruption of a star in the Schwarzschild spacetime: Relativistic effects in the return rate of debris
Tidal disruption of a star in the Schwarzschild spacetime: Relativistic effects in the return rate of debris
复制标题
史瓦西时空中恒星的潮汐破坏：碎片返回率的相对论效应
DOI：
10.1103/physrevd.90.064020
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发表时间：
2014
影响因子：
5
通讯作者：
T. Bogdanović
中科院分区：
文献类型：
--
作者：
R. Cheng;T. Bogdanović
由于瞬变天空的多波长观测覆盖范围的改进，我们研究了非旋转黑洞（BHs）对恒星破坏的相对论效应的重要性。本文的重点是计算碎片返回黑洞的弹道速率，因为这个速率通常被认为与事件的光曲线成正比。我们模拟了不同质量的黑洞（$1{0}^{5},1{0}^{6},1{0}^{7}{M}_{\ensuremath{\bigodot}}$）对低质量主序星的破坏，以及$1{0}^{5}{M}_{\ensuremath{\bigodot}}$黑洞对白矮星的破坏。根据碎片的轨道能量和角动量，我们推断了碎片的轨道分布，并估计了碎片在破坏后的返回率。我们发现了相对论性中断的两个特征：相对于它们的牛顿类比，收益率曲线的逐渐上升和延迟峰值。假设回复率与光曲线成正比，我们发现考虑到当前瞬态巡天的节奏和灵敏度，相对论效应原则上是可测量的。因此，在主序星和白矮星潮汐破坏的情况下，使用一个简单的相对论性相遇模型和牛顿参数拟合的峰值会导致对黑洞质量的高估，分别为$\ensuremath{\sim}\text{few}\ifmmode\times\else\texttimes\fi{}0.1$和$\ensuremath{\sim}\text{few}$。
Motivated by an improved multiwavelength observational coverage of the transient sky, we investigate the importance of relativistic effects in disruptions of stars by nonspinning black holes (BHs). This paper focuses on calculating the ballistic rate of return of debris to the BH as this rate is commonly assumed to be proportional to the light curve of the event. We simulate the disruption of a low mass main sequence star by BHs of varying masses ($1{0}^{5},1{0}^{6},1{0}^{7}{M}_{\ensuremath{\bigodot}}$) and of a white dwarf by a $1{0}^{5}{M}_{\ensuremath{\bigodot}}$ BH. Based on the orbital energy as well as angular momentum of the debris, we infer the orbital distribution and estimate the return rate of the debris following the disruption. We find two signatures of relativistic disruptions: a gradual rise as well as a delayed peak in the return rate curves relative to their Newtonian analogs. Assuming that the return rates are proportional to the light curves, we find that relativistic effects are in principle measurable given the cadence and sensitivity of the current transient sky surveys. Accordingly, using a simple model of a relativistic encounter with a Newtonian parametric fit of the peak leads to an overestimate in the BH mass by a factor of $\ensuremath{\sim}\text{few}\ifmmode\times\else\texttimes\fi{}0.1$ and $\ensuremath{\sim}\text{few}$ in the case of the main sequence star and white dwarf tidal disruptions, respectively.