Abstract

Poster - Splinter SMBHs

Thursday, 10 September 2026, 14:47   (MW-0250)

Improved analytic model for the abundance of Direct Collapse Black Holes

Li Ma, Mihir Kulkarni, and Jens Niemeyer
Institute for Astrophysics and Geophysics, University of Göttingen

Direct collapse black holes (DCBHs) are a strong candidate for the origin of early supermassive black holes (SMBHs). However, it is difficult to accurately estimate the abundance of DCBHs because it heavily depends on the star formation feedback. To solve this problem, we present an improved analytic model to track the conditions needed for DCBH formation. Based on the formalism introduced by Dijkstra et al. (2014), we include the star formation model from the Zeus21 code (Cruz et al. 2025) to better estimate the Lyman-Werner (LW) radiation from Pop II and Pop III stars. We use it to accurately calculate the number densities of halos that receive a critical LW radiation to suppress H2 cooling and remain metal free. Using our analytic model, we can estimate the redshift evolution of the comoving number density of DCBHs during the Cosmic Dawn.