The Early Evolution of Population III.1 Seeded Supermassive Black Holes 20 views

We investigate the properties of Population III.1 seeded supermassive black holes (SMBHs) and their associated host dark matter halos. Using the outputs from cosmological simulations of structure formation, we examine three seeding models that vary the isolation distance governing where Population III.1 seeds can form. For each model, we investigate the multiplicity properties of individual halos as a function of halo mass, formation redshift and number density down to z = 8. We find that single SMBH systems dominate across all models by several orders of magnitude and that multiple systems only represent a fraction less than about 0.1% of all halos hosting SMBHs. Higher multiplicities are shown to be confined within more massive halos and exhibit higher mean formation redshift than single SMBH halos indicating that early formation is required to allow sufficient time for halo mergers. The number density of SMBHs drops with increasing multiplicity across all models. Merger tree analyses tracing back the history of higher multiplicities halos show the increasing rate of mergers at lower redshifts. These analyses provide predictions for the environment and properties of Pop III.1 seeded host systems in the early universe.

BS (Bachelor of Science)

Super massive black holes; Population III.1; Black holes; dark matter

English

2026-05-11