Representing low mass black hole seeds in cosmological simulations: A new sub-grid stochastic seed model

Understand

The nature of the first seeds of supermassive black holes (SMBHs) is currently unknown, with postulated initial masses ranging from $\sim10^5~M_{\odot}$ to as low as $\sim10^2~M_{\odot}$.

• However, most existing cosmological simulations resolve BHs only down to $\sim10^5-10^6~M_{\odot}$.
• In this work, we introduce a novel sub-grid BH seed model that is directly calibrated from high resolution zoom simulations that can trace the formation and growth of $\sim 10^3~M_{\odot}$ seeds forming in halos with pristine, star-forming gas.
• We trace the BH growth along merger trees until their descendants reach masses of $\sim10^4$ or $10^5~M_{\odot}$.