Constraining Primordial Black Holes with Dwarf Galaxy Heating

TL;DR

This paper establishes new constraints on primordial black holes as dark matter candidates by analyzing their heating effects on the Leo T dwarf galaxy's gas, covering a broad mass range relevant to gravitational wave observations.

Contribution

It introduces a novel, cosmology-independent method to limit primordial black hole abundance through interstellar medium heating effects, expanding the mass range constraints.

Findings

Set new limits on PBH abundance in the mass range 1 to 10^7 solar masses.

Demonstrated heating mechanisms can constrain PBHs independently of cosmological assumptions.

Relevant for interpreting gravitational wave signals from intermediate-mass black holes.

Abstract

Black holes formed in the early universe, prior to the formation of stars, can exist as dark matter and also contribute to the black hole merger events observed in gravitational waves. We set a new limit on the abundance of primordial black holes (PBHs) by considering interactions of PBHs with the interstellar medium, which result in the heating of gas. We examine generic heating mechanisms, including emission from the accretion disk, dynamical friction, and disk outflows. Using the data from the Leo T dwarf galaxy, we set a new cosmology-independent limit on the abundance of PBHs in the mass range $\mathcal{O}(1) M_{\odot}-10^7 M_{\odot}$, relevant for the recently detected gravitational wave signals from intermediate-mass BHs.