论文标题
在AGN积聚磁盘中同步EMRI和IMRIS
Synchronizing the EMRIs and IMRIs in AGN accretion disks
论文作者
论文摘要
极端质量比率灵感（EMRI）和中间质量比率灵感（IMRIS）是激光干涉仪空间天线（LISA）的重要重力波（GW）源。到目前为止，它们的形成和进化被认为是独立的，但是最近的理论表明，恒星质量的黑洞（SBHS）和中间质量黑洞（IMBHS）可以在活性银河核（AGN）的增生盘中共存，这表明EMRIS和IMRIS可能在同一位置形成。在迁移到原星盘中的气体巨人可能会捕获靠近其轨道的行星的动机，我们在本文中研究了AGN磁盘中的间隙IMBH与周围的SBHS之间的类似相互作用。我们通过磁盘和IMBH对SBHS施加的扭矩进行分析，并表明如果IMBH在IMBH的轨道内，则可以将SBH捕获。然后，我们在数值模拟中实施扭矩，以研究嵌入AGN磁盘中的外IMBH和内部SBH的迁移。我们发现它们的迁移是同步的，直到它们到达中央超级黑洞的距离大约十个Schwarzschild Radii，由于GW辐射强，两人在那里分解。该结果表明，丽莎可以在同一AGN的几年内检测到EMRI和IMRI。这样的GW来源将带来有关AGN中SBH和IMBH的形成和演变的丰富信息。
Extreme-mass-ratio inspirals (EMRIs) and intermediate-mass-ratio inspirals (IMRIs) are important gravitational-wave (GW) sources for the Laser Interferometer Space Antenna (LISA). So far, their formation and evolution are considered to be independent, but recent theories suggest that stellar-mass black holes (sBHs) and intermediate-mass black hole (IMBHs) can coexist in the accretion disk of an active galactic nucleus (AGN), which indicates that EMRIs and IMRIs may form in the same place. Motivated by the fact that a gas giant migrating in a protoplanetary disk could trap planetesimals close to its orbit, we study in this paper a similar interaction between a gap-opening IMBH in an AGN disk and the sBHs surrounding it. We analyse the torques imposed on the sBHs by the disk as well as by the IMBH, and show that the sBHs can be trapped by the IMBH if they are inside the orbit of the IMBH. Then we implement the torques in our numerical simulations to study the migration of an outer IMBH and an inner sBH, both embedded in an AGN disk. We find that their migration is synchronized until they reach a distance of about ten Schwarzschild radii from the central supermassive black hole, where the pair breaks up due to strong GW radiation. This result indicates that LISA may detect an EMRI and an IMRI within several years from the same AGN. Such a GW source will bring rich information about the formation and evolution of sBHs and IMBHs in AGNs.
