Unraveling the seeds of supermassive black holes using a multi-scale suite of cosmological simulations

One of the biggest gaps in our understanding of the earliest galaxy assembly, is the origin of supermassive black holes. Possible candidates include black holes that collapse directly from gas, as well as those that form from the earliest generation of stars, remnants of runaway stellar collisions, or black holes in dense clusters of stars. These channels are expected to take place in very early times. However, they are challenged by the masses and number of black holes that are observed at these early times. Researchers at the University of Virginia will implement novel theoretical models for the formation of supermassive black holes that will be crucial in interpreting the observations, with the goal of unveiling the SMBH origins. As part of the project, the researchers will build a teacher training program to develop related classroom content for K-12 teachers. Current cosmological simulations cannot fully leverage the upcoming wealth of gravitational wave and electromagnetic observations. A key limitation of large cosmological simulations is their simplistic treatment of the multiphase interstellar medium (ISM) via an effective equation of state. The key science goal is to build a multi-scale suite of cosmological hydrodynamic simulations that will identify distinct gravitational wave and electromagnetic signatures of Population III, nuclear star cluster and direct collapse black hole seeds, detectable within the James Webb Space Telescope and next generation facilities like ngVLA, extremely large telescopes and LISA. To achieve this, a large systematic study of the formation and growth rates of different seeds within explicit-ISM simulations will be conducted, accompanied by a characterization of the host galaxies of seed descendants and comparisons with recent observations. The work should lead to predictions of the LISA gravitational wave event rates for the various black hole seeding channels. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.