Tidal disruption events from supermassive black hole binaries
Tidal disruption events from supermassive black hole binaries
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DOI：
10.1093/mnras/stw2913
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发表时间：
2017-03-01
影响因子：
4.8
通讯作者：
Begelman, Mitchell C.
中科院分区：
文献类型：
--
作者：
Coughlin, Eric R.;Armitage, Philip J.;Begelman, Mitchell C.
本文研究了超大质量黑洞双星对恒星潮汐扰动的扰动前引力动力学和扰动后流体动力学。我们关注的是具有相对较低质量的主星（10（6）M圆点），中等质量比，以及具有相当长的引力波螺旋时间（数万年）的分离的双星。首先，我们产生一个大的合奏（1和10万之间）的限制三体积分，以量化的统计特性的潮汐中断最初未绑定的恒星的圆形SMBH二进制。与单个SMBH的参考情况相比，二元势在破裂点处引起星星的比能量和角动量的显着变化。第二，我们使用牛顿数值流体力学的详细演变的后备碎片从120中断随机选择的三体合奏（不包括最深的穿透遇到）。我们发现，碎片的整体形态被大大改变的存在下的第二个黑洞，吸积率的历史显示了广泛的行为，包括数量级下降和过剩相对于控制模拟，包括只有一个黑洞。复杂的演化通常持续许多轨道周期的联星。我们发现证据的权力在吸积曲线的时间尺度相关的双轨道周期，虽然没有确切的周期性。我们讨论了我们的研究结果在未来的宽场调查的背景下，并评论的前景，确定和表征的事件发生在核与二进制SMBHs的子集。
We investigate the pre-disruption gravitational dynamics and post-disruption hydrodynamics of the tidal disruption of stars by supermassive black hole (SMBH) binaries. We focus on binaries with relatively low mass primaries (10(6) M-circle dot), moderate mass ratios, and separations with reasonably long gravitational wave inspiral times (tens of Myr). First, we generate a large ensemble (between 1 and 10 million) of restricted three-body integrations to quantify the statistical properties of tidal disruptions by circular SMBH binaries of initially unbound stars. Compared to the reference case of a disruption by a single SMBH, the binary potential induces a significant variance into the specific energy and angular momentum of the star at the point of disruption. Second, we use Newtonian numerical hydrodynamics to study the detailed evolution of the fallback debris from 120 disruptions randomly selected from the three-body ensemble (excluding only the most deeply penetrating encounters). We find that the overall morphology of the debris is greatly altered by the presence of the second black hole, and the accretion rate histories display a wide range of behaviours, including order of magnitude dips and excesses relative to control simulations that include only one black hole. Complex evolution typically persists for many orbital periods of the binary. We find evidence for power in the accretion curves on time-scales related to the binary orbital period, though there is no exact periodicity. We discuss our results in the context of future wide-field surveys, and comment on the prospects of identifying and characterizing the subset of events occurring in nuclei with binary SMBHs.