Symbiosis or not: the interplay of massive black holes and their host galaxies

这个项目的目的是揭示大质量黑洞及其宿主星系各种增长途径的重要性。这将通过确定附近星系中大质量黑洞的质量，通过动力学模型描述恒星的运动，并通过大质量黑洞和星系形成的情景来解释。大质量黑洞被认为在塑造星系和星际物质方面发挥了重要作用。这一点从大质量黑洞的质量与宿主星系的全球属性(如质量或光度)之间的经验标度关系中可见一斑。这种关联非常紧密，但散布很小，但我们不知道为什么，也不知道为什么大质量黑洞和它们的宿主星系共生生长，或者是一个成分在它们的演化中占主导地位。观测困难的结果是，标度关系仍然鲜为人知，黑洞质量通常只在某些类型的星系中得到，黑洞的增长过程甚至在存在黑洞质量的星系中也不受限制。该项目利用自适应光学积分场光谱学提供最先进的观测，以便在一系列星系属性中得出大量黑洞质量的测量结果(约占测量总数的20%)。特别是，这将通过测量恒星的运动并用它来约束动力学模型来实现。动力学模型将提供黑洞质量和恒星轨道类型的详细信息。所采用的方法将测试黑洞质量测定相对于星系暗物质含量假设的稳健性，有可能成为该领域的标准。选择该样本来探测标度关联中的缺口，并调查描述大质量黑洞增长的情景。在共生增长的情况下，大质量黑洞通过祖先黑洞的合并而增长，而在另一种情况下，它们通过气体的吸积增长。这两种情景在星系中心区域恒星的轨道上留下了不同的印记：合并情景预测了接近大质量黑洞的轨道将出现赤字，因为这些恒星被从原子核抛出。有了大多数必要的工具和所有数据在手，就有可能确定黑洞质量，描述大质量黑洞附近恒星的运动，并区分相互竞争的情景。

The aim of this project is to unravel the importance of various pathways of growth of massive black holes and their host galaxies. This will be done by determining the masses of massive black holes in nearby galaxies, describing the motion of stars via dynamical models and interpreting these through scenarios of massive black hole and galaxy formation. Massive black holes are thought to have played a major role in shaping galaxies and intergalactic matter. This is evident from the empirical scaling relations between the masses of massive black holes and the global properties of host galaxies, such as their mass or luminosity. The correlation is very tight with a small scatter, but we do not understand why, nor if the massive black holes and their host galaxies grow symbiotically or one component dominates in their evolution. The consequence of the observing difficulties is that the scaling relations are still poorly known, black hole masses are typically derived in only some types of galaxies and the black hole growth processes are not even constrained in galaxies for which black hole masses exist. This project provides the state-of-art observation with adaptive optics integral-field spectroscopy in order to derive a significant number of measurements of black hole masses (~20% increase to the total number of measurements), over a range of galaxy properties. In particular, this will be achieved by measuring the motions of stars and using it to constrain dynamical models. The dynamical models will provide the black hole masses and the detailed information on the types of stellar orbits. The methods applied will test the robustness of the black hole mass determinations with respect to the assumptions on the dark matter content of galaxies, with a potential for becoming the standard in the field. The sample is selected to probe the gaps in the scaling correlations, and to investigate the scenarios describing the growth of massive black holes. In a symbiotic growth scenario, massive black holes grow through merging of progenitor black holes, while in the other they grow by accretion of gas. The two scenarios leave different imprints on the orbits of stars in the central regions of galaxies: the merger scenario predicts a deficit of orbits which come close to the massive black holes, as those stars are ejected from the nucleus. With most of the necessary tools and all data already in hand, it will be possible to determined the black hole masses, characterise the motion of stars in the vicinity of massive black holes and distinguish between competing scenarios.