Black hole formation via gas-dynamical processes

TL;DR

This paper explores how gas dynamical processes, including isothermal collapse and atomic hydrogen cooling, can lead to the formation of massive black holes in the early universe, with insights from cosmological simulations.

Contribution

It presents a detailed analysis of gas inflow mechanisms and their role in forming supermassive black hole seeds, including simulation results and alternative pathways.

Findings

Large inflow rates (~0.1 solar masses/year) can be achieved via isothermal collapse with atomic hydrogen cooling.

Cosmological simulations support the viability of gas dynamical processes in black hole seed formation.

Alternative pathways involve trace metals and molecular hydrogen, expanding possible formation scenarios.

Abstract

Understanding the formation of earliest supermassive black holes is a question of prime astrophysical interest. In this chapter, we focus on the formation of massive black holes via gas dynamical processes. The necessary requirement for this mechanism are large inflow rates of about 0.1 solar mass per year. We discuss how to obtain such inflow rates via an isothermal collapse in the presence of atomic hydrogen cooling, and the outcome of such a collapse from three dimensional cosmological simulations in subsection 2.2. Alternatives to an isothermal direct collapse are discussed in subsection 3 which include trace amounts of metals and/or molecular hydrogen. In the end, we briefly discuss future perspectives and potential detection of massive black hole seeds via upcoming missions.