Black Holes and Galaxy Evolution

AST-0071099Merritt拟议中的研究将使用复杂的N体模拟来研究星系-超大质量黑洞在星系动力学中的联系。HST-STIS摄谱仪可以用来测量星系核中的速度色散和速度梯度，这可以用来检验这些模拟结果的预测。几乎所有星系的中心都含有超大质量黑洞，这几乎可以肯定是类星体时代的遗迹，当时黑洞吸积气体并产生巨大的光度。这些黑洞现在几乎处于静止状态，平均只占其宿主星系质量的0.3%。越来越多的研究表明，遗迹黑洞的引力影响可以远远超出星系的中心。此外，黑洞的形成和生长可能与更大尺度上的星系演化密切相关。例如，包含核黑洞的星系之间的合并将产生超大质量的黑洞双星，它们最终会合并，同时发出引力辐射。拟议中的研究将通过研究黑洞与其宿主星系之间的联系来解决这些问题。这项工作的一个主要组成部分将是对超大质量黑洞双星的研究。这些双星的形成和衰变可能与许多现象有关。 另一个目标是了解黑洞如何通过影响单个恒星的运动来影响其宿主星系的动力学状态。这项工作需要大量的计算，依赖于最先进的N体代码和大规模并行超级计算机。

AST-0071099MerrittThe proposed research will use sophisticated N-body simulations to study the galaxy--supermassive black hole connection in galactic dynamics. The HST-STIS spectrograph can be used to measure velocity dispersions and velocity gradients in galaxy nuclei which can be used to test the predictions resulting from these simulations.Virtually all galaxies appear to contain supermassive black holes at their very centers, which are almost certainly relics of the quasar era when the black holes accreted gas and generated enormous luminosities. These black holes are now nearly quiescent and comprise on average only ~0.3% of the mass of their host galaxies. There is a growing body of work suggesting that the gravitational influence of the relic black holes can extend far beyond the center of a galaxy. Moreover, the formation and growth of black holes may be intimately connected with the evolution of galaxies on larger scales. For instance, mergers between galaxies containing nuclear black holes would produce supermassive black-hole binaries which would eventually coalesce while emitting gravitational radiation. The proposed research would address these questions by studying the link between black holes and their host galaxies. A major component of the work would be a study of supermassive black hole binaries. The formation and decay of these binaries may be relevant to a wide range of phenomena. Another goal is to understand how black holes affect the dynamical state of their host galaxies by influencing the motions of individual stars. The work would be heavily computational, relying on state-of-the-art N-body codes and massively parallel supercomputers.***