Most cosmological simulations of galaxy evolution include active galactic nucleus ( AGN ) feedback , typically seeding black holes with masses of \geq 10 ^ { 5 } h ^ { -1 } M _ { \sun } when the dark matter halo exceeds a given threshold mass . introduced a new model , which seeds black holes at 10 ^ { 3 } h ^ { -1 } M _ { \sun } based on gas properties alone , and motivated by the channel of black hole formation due to the collapse of the most massive first stars in the Universe .
We compare the black hole mass when the dark matter halo mass is 10 ^ { 10 } h ^ { -1 } M _ { \sun } between the different seeding methods .
We find that seeding based upon gas properties gives a distribution of black hole masses with \langle \log M _ { BH } { / M _ { \sun } } \rangle = ( 5.18 \pm 0.54 ) when dark matter halo mass is 10 ^ { 10 } h ^ { -1 } M _ { \sun } , consistent with the seeding criteria used in other simulations .
However , the evolution of individual galaxies can be strongly affected by the different seeding mechanisms .
We also find that the mean value of the distribution of black hole masses at a given halo mass evolves over time , with higher masses at higher redshifts , indicative of downsizing .
Our results can inform more physically motivated black hole and AGN feedback models in cosmological simulations and semi-analytic models .