论文标题
密集的恒星环境中的巨大黑洞形成：高速分散核星簇中的X射线检测率提高
Massive black hole formation in dense stellar environments: Enhanced X-ray detection rates in high velocity dispersion nuclear star clusters
论文作者
论文摘要
我们分析了托有核星形簇（NSC）的108个星系的Chandra X射线天文台成像，以搜索大型黑洞（BHS）的签名。 NSC是非常密集的恒星环境，理论上可以促进大规模BH形成。 Stone等人的最新工作。 （2017年）发现，通过潮汐捕获，足够致密的NSC应该不稳定恒星质量BH的巨大BH增长到大规模的BH中。此外，还有一个速度分散阈值（$ 40 \; \ rm {km \ \; s^{ - 1}} $），不可避免地会形成大量的BH。为了提供这些理论的观察性测试，我们测量了NSC的X射线发射，并将其与测量的速度分散和潮汐捕获失控的时间表进行比较。我们发现，$ 40 \; \ rm {km \; s^{ - 1}} $阈值的NSC被以下面的速率（考虑到X射线二进制污染的污染物）的X射线。这些结果与一个浓密的高速NSC可以形成大量BHS的情况一致，提供了不依赖于高红移的条件的地层途径。
We analyze Chandra X-ray Observatory imaging of 108 galaxies hosting nuclear star clusters (NSCs) to search for signatures of massive black holes (BHs). NSCs are extremely dense stellar environments with conditions that can theoretically facilitate massive BH formation. Recent work by Stone et al. (2017) finds that sufficiently dense NSCs should be unstable to the runaway growth of a stellar mass BH into a massive BH via tidal captures. Furthermore, there is a velocity dispersion threshold ($40\;\rm{km\;s^{-1}}$) above which NSCs should inevitably form a massive BH. To provide an observational test of these theories, we measure X-ray emission from NSCs and compare to the measured velocity dispersion and tidal capture runaway timescale. We find that NSCs above the $40\;\rm{km\;s^{-1}}$ threshold are X-ray detected at roughly twice the rate of those below (after accounting for contamination from X-ray binaries). These results are consistent with a scenario in which dense, high-velocity NSCs can form massive BHs, providing a formation pathway that does not rely on conditions found only at high redshift.
