Multimessenger Signatures of Massive Black Holes in Dwarf Galaxies

TL;DR

This study uses high-resolution cosmological simulations to analyze the properties and observability of massive black holes in dwarf galaxies, highlighting their potential for gravitational wave detection despite low luminosities.

Contribution

It provides new insights into the occurrence, location, and merger history of MBHs in dwarf galaxies based on detailed simulations.

Findings

Larger dwarf galaxies are more likely to host MBHs.

About 50% of MBHs are wandering outside the galaxy center.

MBHs have low accretion luminosities, making them hard to detect.

Abstract

Recent discoveries of massive black holes (MBHs) in dwarf galaxies suggest that they may have a more common presence than once thought. Systematic searches are revealing more candidates, but this process could be accelerated by predictions from simulations. We perform a study of several high-resolution, cosmological, zoom-in simulations focusing on dwarf galaxies that host massive black holes at z = 0, with the aim of determining when the black holes are most observable. Larger dwarf galaxies are more likely to host MBHs than those of lower mass. About 50% of the MBHs in dwarfs are not centrally located, but rather are wandering within a few kpc of the galaxy center. The accretion luminosities of MBHs in dwarfs are low throughout cosmic time, rendering them extremely difficult to detect. However, the merger history of these MBHs is optimal for gravitational wave detection by LISA.