Massive black holes (MBHs) are ubiquitous in luminous galaxies, and their mass is correlated with the properties of the host galaxy. It is therefore plausible that MBHs played an important role in the formation of structure in the Universe. This project will study the early coevolution of MBHs and their host galaxies, at the end of the cosmic dark ages. The research will examine key physical processes, including the hierarchical merging of dark matter halos; heating, cooling, and gas inflow inside the first HII regions; how to establish steady accretion onto the first black holes; global angular-momentum-transporting gravitational instabilities; the onset of fragmentation and star formation; establishing the first multiphase dusty interstellar medium; radiative and mechanical launching of winds and outflows; and the merging of smaller black holes into larger ones. These processes are complex and involve multiple physical scales, so large-scale numerical simulations will be developed to accompany the analytical methods being used. In order to pay careful attention to numerical accuracy and systematics, those simulations will use multiple methods, including smoothed-particle hydrodynamics, grid-based hydrodynamics with adaptive mesh refinement, and appropriate radiation transfer and sink-particle stellar dynamics. The results will address some of the key open questions in cosmology, including how the first galaxies formed, whether the MBH or the host stellar system came first, and when was the tight correlation between MBHs and hosts established in different environments?
Because this research addresses the observable spectral properties of the first objects, it will be a valuable guide for astronomical searches with the next-generation of infrared facilities. It will also help to reduce theoretical uncertainties in estimates of low-frequency gravitational radiation bursts. Involved graduate and undergraduate students will learn cutting-edge methodologies with many and varied applications. Unprecedented animations of the first galaxies and early black hole accretion flows will be used in teaching and to disseminate knowledge about one of the least well-understood epochs in the evolution of structure in the Universe. This research will assist Dr Bromm as he continues to write articles for the popular science press.
