Interstellar Gas Heating by Primordial Black Holes

TL;DR

This paper investigates how primordial black holes can heat interstellar gas, providing constraints on their abundance across a wide mass range using observational data, which informs their role as dark matter candidates.

Contribution

It offers a comprehensive analysis of gas heating by PBHs, including emission mechanisms and observational constraints from dwarf galaxies and galactic systems.

Findings

Constraints on PBH abundance over a broad mass range.

Analysis of PBH emission mechanisms affecting gas heating.

Implications for PBHs as dark matter candidates.

Abstract

Interstellar gas heating is a powerful cosmology-independent observable for exploring the parameter space of primordial black holes (PBHs) formed in the early Universe that could constitute part of the dark matter (DM). We provide a detailed analysis of the various aspects for this observable, such as PBH emission mechanisms. Using observational data from the Leo T dwarf galaxy, we constrain the PBH abundance over a broad mass-range, $M_{\rm PBH} \sim \mathcal{O}(1) M_{\odot}-10^7 M_{\odot}$, relevant for the recently detected gravitational wave signals from intermediate-mass BHs. We also consider PBH gas heating of systems with bulk relative velocity with respect to the DM, such as Galactic clouds.