Black hole mergers: the first light
Black hole mergers: the first light
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黑洞合并：第一道曙光
DOI：
10.1111/j.1365-2966.2009.15802.x
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发表时间：
2009
影响因子：
4.8
通讯作者：
A. King
中科院分区：
文献类型：
--
作者：
E. Rossi;G. Lodato;G. Lodato;P. Armitage;J. Pringle;A. King
超大质量黑洞双星的合并是通过引力波的发射发生的，引力波可以给合并的黑洞带来巨大的反冲。我们考虑的能量耗散，结果，如果反冲黑洞是由一个薄circumbinary盘包围。我们的研究结果与以往的研究结果有很大的不同。我们分析表明，能源的主要来源往往是潜在的能量，释放气体在外盘试图在较小的半径圆化。因此，仅包括圆盘气体获得的动能的量纲估计低估了真实的能量损失。这种低估可以超过一个数量级，如果反冲是直接接近光盘平面。我们使用三维光滑粒子流体动力学（SPH）模拟和二维有限差分模拟来验证我们的分析估计。我们还计算了测辐射热的光变曲线，这被发现强烈依赖于踢角。对于反冲速度超过~ 103 km s-1的低质量（106 M反冲）黑洞，由于这种机制，可以观测到一个快速的发射信号。早期的辐射主要是由于黑洞合并时圆盘对质量损失的反应。我们用解析的方法推导出这种情况发生的条件。
The coalescence of supermassive black hole binaries occurs via the emission of gravitational waves, that can impart a substantial recoil to the merged black hole. We consider the energy dissipation that results if the recoiling black hole is surrounded by a thin circumbinary disc. Our results differ significantly from those of previous investigations. We show analytically that the dominant source of energy is often potential energy, released as gas in the outer disc attempts to circularize at smaller radii. Thus, dimensional estimates, that include only the kinetic energy gained by the disc gas, underestimate the real energy loss. This underestimate can exceed an order of magnitude, if the recoil is directed close to the disc plane. We use three dimensional smooth particle hydrodynamics (SPH) simulations and two-dimensional finite difference simulations to verify our analytic estimates. We also compute the bolometric light curve, which is found to vary strongly depending upon the kick angle. A prompt emission signature due to this mechanism may be observable for low-mass (10 6 M ☉ ) black holes whose recoil velocities exceed ~10 3 km s -1 . Emission at earlier times can mainly result from the response of the disc to the loss of mass, as the black holes merge. We derive analytically the condition for this to happen.