Stellar Dynamics Around Black Holes in Galactic Nuclei

AST 0206038Touma在过去的十年里，由于哈勃太空望远镜（HST）对星系核的高分辨率观测，在二十多个星系（包括银河系）中发现了超大质量黑洞（SBH）。这些探测依赖于测量黑洞对附近气体和恒星施加的可感知的动力学效应。Touma博士将对星系核中SBH周围的恒星动力学进行详细研究。这项研究将通过对运动学观测进行仔细的动力学建模来加强探测工作。这也将有助于澄清SBH在塑造宿主星系中心区域特征方面所扮演的角色。最后，它将揭示一些有关SBH的起源和演变的问题。 特别是，它将涉及对图马博士最近发现的暴力不稳定的彻底分析。这种不稳定性会影响恒星盘，这些恒星盘的中心由SBH控制，并且有一小部分反向旋转的恒星。这种不稳定性将盘扭曲成一个不平衡的形状，并有望解释仙女座星系（M31）的不平衡核，它拥有一个SBH，并被怀疑支持一小部分反向旋转的恒星。

AST 0206038ToumaOver the last decade, thanks to high-resolution observations of galactic nuclei by the Hubble Space Telescope (HST), supermassive black holes (SBHs) have been detected in two dozen or so galaxies (including the Milky Way). These detections rely on the measurement of the appreciable dynamical effects that a black hole exerts on nearby gas and stars. Dr. Touma will conduct a detailed study of stellar dynamics around SBHs in galactic nuclei. This study will bolster detection efforts through careful dynamical modeling of kinematic observations. It will also help to clarify the role that a SBHs play in shaping features found in the central regions of the host galaxy. Finally, it will shed some light on questions relating to the origin and evolution of SBHs. In particular, it will involve a thorough analysis of a violent instability that Dr. Touma has recently identified. This instability affects stellar disks which are dominated by a SBH in their center, and which harbor a small proportion of counter-rotating stars. The instability distorts the disk into a lopsided shape and promises to explain the lopsided nucleus of the Andromeda Galaxy (M31), which harbors an SBH, and is suspected of supporting a small percentage of counter-rotating stars.***