Counting black holes: The cosmic stellar remnant population and implications for LIGO
Counting black holes: The cosmic stellar remnant population and implications for LIGO
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DOI：
10.1093/mnras/stx1959
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发表时间：
2017-03
影响因子：
4.8
通讯作者：
Oliver D. Elbert;J. Bullock;M. Kaplinghat
中科院分区：
文献类型：
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作者：
Oliver D. Elbert;J. Bullock;M. Kaplinghat
作者(S)：Elbert，Oliver D；Bullock，James S；Kaplinghat，Manoj|摘要：我们提出了一个解释双星黑洞合并引力波信号的经验方法，假设潜在的黑洞群来自恒星演化的残余物。利用观测到的星系质量和恒星金属丰度之间的关系，我们预测了黑洞计数是星系恒星质量的函数。例如，我们指出，一个像银河系这样的星系应该拥有数百万个$\sim 30~M_\odt$黑洞，而像Draco这样的矮小卫星星系应该拥有$\sim 100$这样的残余物，对假定的IMF和恒星演化模型的依赖性很弱。大多数低质量黑洞($SIM10 M_ODOT$)通常位于大质量星系($M_STAR\SIEQ 10^{11}M_\ODOT$)内，而大质量黑洞($SIM 50~M_\ODOT$)通常位于矮星系($M_\ODOT\SMEQ 10^9 M_\ODOT$)内。如果在一个二元黑洞合并中涉及大约$1$的黑洞，那么来自Advanced LIGO的报告的合并率密度可以适应一系列合并时间标度，并且在下一个十年内应该可以检测到包含$g50~M\ODOT$个黑洞的合并。识别合并的宿主星系群体提供了一种限制双星中子星或黑洞形成效率和合并时间尺度分布的方法；如果合并时间尺度与宇宙年龄相比较短，这些事件将主要局限于矮小星系，否则将主要局限于大质量星系。随着探测到更多的合并，直接通过探测双中子星合并的电磁对应物或间接通过事件的各向异性来确定宿主星系群的前景将成为现实的可能性。
Author(s): Elbert, Oliver D; Bullock, James S; Kaplinghat, Manoj | Abstract: We present an empirical approach for interpreting gravitational wave signals of binary black hole mergers under the assumption that the underlying black hole population is sourced by remnants of stellar evolution. Using the observed relationship between galaxy mass and stellar metallicity, we predict the black hole count as a function of galaxy stellar mass. We show, for example, that a galaxy like the Milky Way should host millions of $\sim 30~M_\odot$ black holes and dwarf satellite galaxies like Draco should host $\sim 100$ such remnants, with weak dependence on the assumed IMF and stellar evolution model. Most low-mass black holes ($\sim10 M_\odot$) typically reside within massive galaxies ($M_\star \simeq 10^{11} M_\odot$) while massive black holes ($\sim 50~M_\odot$) typically reside within dwarf galaxies ($M_\odot \simeq 10^9 M_\odot$) today. If roughly $1\%$ of black holes are involved in a binary black hole merger, then the reported merger rate densities from Advanced LIGO can be accommodated for a range of merger timescales, and the detection of mergers with $g 50~M_\odot$ black holes should be expected within the next decade. Identifying the host galaxy population of the mergers provides a way to constrain both the binary neutron star or black hole formation efficiencies and the merger timescale distributions; these events would be primarily localized in dwarf galaxies if the merger timescale is short compared to the age of the universe and in massive galaxies otherwise. As more mergers are detected, the prospect of identifying the host galaxy population, either directly through the detection of electromagnetic counterparts of binary neutron star mergers or indirectly through the anisotropy of the events, will become a realistic possibility.