Project Details
Projekt
Supermassive black holes, accretion discs, stellar dynamics and tidal disruptions
Applicant
Professor Pau Amaro-Seoane, Ph.D.
Subject Area
Astrophysics and Astronomy
Term
from 2013 to 2020
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 233738862
Massive black holes exist at the centre of most, perhaps all galaxies. The masses of the black holes are very well correlated with the properties of their host galaxies, suggesting that the formation of both populations are linked. Moreover, galaxies form hierarchically, from the merger of smaller galaxies. I propose to study the fate of the black hole binaries (BBH) formed during galaxy mergers. I plan to answer whether the BBH merge or stall at sub-parsec separations. The research group will focus on (i) tidal disruptions of stars and (ii) the evolution of BBH in gas-rich environments, from parsec separations, but also until they reach the gravitational-wave-driven phase. We will calculate the rate tidal disruptions in the process and also of decay of the binary at different stages, depending on the thermodynamics of the surrounding gas, including the effect of the stars formed in this gas. Once the BBH reaches separations of the order of a hundred Schwarzschild radii, the orbit decays due to the emission of gravitational waves and the binary decouples from the disc. However, some gas is expected to remain bound to the black holes. We will study the evolution of this gas and predict the strength of its electromagnetic emission just before the BBH coalesce. This will increase the scientific output of its gravitational wave detection. We also plan on a post-processing of the simulations described above, to identify observational features that reveal the presence of BBHs. These predictions will be crucial in guiding electromagnetic searches for such systems in current and upcoming time-domain and spectral large-sky surveys. This would allow us to put stringent limits on the origin and evolution of the massive black hole population.
DFG Programme
Research Grants
International Connection
Chile, Italy
