Massive Black Holes (MBHs) populate the centres of most, if not all, galaxies with total masses greater than approximately 1e12 solar masses.
The project outlined here aims to uncover firstly the formation pathways of MBHs and secondly to track the evolution and growth of MBHs in very early galaxies as the MBHs grow, merge and settle towards their host galaxy's centre. Moreover, recent observations by JWST have shown that MBHs are active in galaxies with redshifts up to z ~ 10.6 (Larson et al. (2023), Maiolino et al (2023)).
What this tells us is that the seeding mechanisms for MBHs occured in the very early Universe and produced seeds which grow to up to one million times the mass of the Sun in only a few hundred million years (the age of the Universe at z = 10.6 is approximately 430 Myr). What is currently unclear are the exact seeding mechanisms for the MBHs observed and what their potential growth rates are.
This proposal represents the first phase of a three phase undertaking. In this first phase we will run simulations which seed haloes with light and/or heavy seeds. The simulations will be conducted within a 9 Mpc**3 volume with a maximum physical resolution of approximately 1 pc and a mass resolution of approximately 1000 solar masses.
The goal is to evolve the simulations to a redshift of z = 10. In this phase the light seeds will have masses of less than 300 solar masses and will be spawned by PopulationIII (PopIII) stars. Heavy seeds on the other hand will be spawned by so-called super-massive stars.
The seeding mechanisms will be based on the environmental properties of the halo and are backboned by high-resolution simulations of individual haloes which are guiding our calibration of individual stellar masses (Regan et al. (2018b), Wise et al. (2019), Prole et al. (2022), Regan et al. (2023)) including SMSs. EuroHPC resources will advance this project significantly and crucially by allowing us to run cosmological simulations and to seed thousands of galaxies with both light and heavy seeds in this way and to explore the growth of the seeds via these pathways.
The results of the simulations can be directly compared against current and near-future JWST surveys.
Maynooth University, Ireland.