On the Prevalence of Super-Massive Black Holes over Cosmic Time

Understand

We investigate the abundance of Super-Massive Black Hole (SMBH) seeds in primordial galaxy halos.

• We explore the assumption that dark matter halos outgrowing a critical halo mass M_c have some probability p of having spawned a SMBH seed.
• Current observations of local, intermediate-mass galaxies constrain these parameters: For $M_c=10^{11}M_\odot$, all halos must be seeded, but when adopting smaller M_c masses the seeding can be much less efficient.
• The constraints also put lower limits on the number density of black holes in the local and high-redshift Universe.