The coevolution of massive compact ellipticals and their black holes at high redshift

该项目详细研究了大质量致密演化的椭圆星系及其高红移黑洞的起源。这些星系的恒星形成率非常低，比现在的椭圆体小三到五倍，质量密度比低红移的星系高一到两个数量级。我们将首次使用宇宙体积中大质量星系的统计样本的亚千帕秒分辨率的宇宙变焦模拟来解决两个基本的物理问题：1)大质量高红移球体中的黑洞是如何增长的，以及哪个过程负责终止这些系统中的恒星形成？它主要是来自中心超大质量黑洞的反馈，还是来自大质量恒星爆发的风，或者仅仅是非常高效的气体消耗，或者是两者的结合？2)为什么高红移椭圆如此紧凑，什么是快速大小演变的主要驱动力？有强有力的理论证据表明，较小的(贫气)合并对于大小和密度的强烈演化比主要合并更重要，特别是对于高红移的大质量星系。我们将详细探讨这种增长机制。在资助期结束时，我们预计能够回答这两个问题。

This project proposes a detailed investigation of the origin of massive compact evolved elliptical galaxies and their black holes at high redshift. These galaxies have very low star formation rates, are three to five times smaller than present day ellipticals and have one to two orders of magnitude higher mass densities than their low redshift counterparts. We will, for the first time, use sub kiloparsec resolution cosmological ”zoom” simulations of a statistical sample of massive galaxies in a cosmological volume to address two fundamental physical questions: 1) How do black holes in massive high redshift spheroids grow and which process is responsible for the termination of star formation in these systems? Is it mainly feedback from a central super-massive black hole, winds from a massive starburst or simply very efficient gas consumption or a combination? 2) Why are the high redshift ellipticals so compact and what is the main driver for the rapid size evolution? There is strong theoretical evidence that minor (gas poor) mergers are more important for the strong evolution in size and density than major mergers, in particular for massive galaxies at high redshift. This growth mechanism will be explored in detail. At the end of the funding period we expect to be able to answer both questions.