A Lower Bound on the Mass of Compact Objects from Dissipative Dark Matter

TL;DR

This paper establishes a theoretical lower bound on the mass of dark compact objects formed from dissipative dark matter, showing that such objects can be lighter than stellar counterparts under certain conditions.

Contribution

It introduces a model for the formation of low-mass dark compact objects, deriving a minimum mass limit based on thermo-chemical evolution and opacity constraints.

Findings

Dark matter halos can produce low-mass compact objects.

The minimum fragment mass depends on the thermal evolution during collapse.

Dark compact objects can be lighter than stellar remnants.

Abstract

We study the minimum mass of dark compact objects formed in dissipative dark-matter halos and show that the simple atomic-dark-matter model consistent with all current observations can create low-mass fragments that can evolve into compact objects forbidden by stellar astrophysics. We model the collapse of the dark halo's dense core by tracing the thermo-chemical evolution of a uniform-density volume element under two extreme assumptions for density evolution: hydrostatic equilibrium and pressure-free collapse. We then compute the opacity-limited minimum fragment mass from the minimum temperature achieved in these calculations.