Black hole seeds from Self-Interacting Dark Matter halos

Abstract

We examine the possible formation of black holes via gravothermal collapse of the cores of self-interacting dark matter (SIDM) halos. We first use a well established model (Ludlow et al. 2014) to calculate accretion histories for cold dark matter (CDM) halos, and the relation between a halo’s mass and its concentration. This allows us to have the parameters for the initial conditions of the SIDM halos. With this relation established, we then proceed to calculate how long it takes for a black hole to form from an SIDM halo after the halo has formed a core due to self-interactions, and how massive the resulting black hole is, following the results of Pollack et al. 2015. Over the examined mass range of 10^-5 - 10^15 M_Sun, our results show that halos of current day mass 10^8 – 10^11 MSun are capable of collapsing into black holes in the least amount of time, forming black holes of masses 10^4 – 10^8 M_Sun in less than 5 Gyrs, as long as the cross section σ/m is larger than 50 cm^2 g^-1.