Roman CCS White Paper: Characterizing the Galactic population of isolated black holes

TL;DR

This paper discusses strategies to utilize the Roman Space Telescope for detecting and characterizing the Milky Way's estimated 100 million isolated black holes, significantly advancing our understanding of their properties and astrophysical implications.

Contribution

It outlines a comprehensive observation strategy and software pipeline improvements to maximize Roman's potential in discovering isolated black holes.

Findings

Roman can potentially identify a large population of isolated black holes.

Optimized observation strategies increase detection likelihood.

Ground-based follow-up complements space-based observations.

Abstract

Although there are estimated to be 100 million isolated black holes (BHs) in the Milky Way, only one has been found so far, resulting in significant uncertainty about their properties. The Galactic Bulge Time Domain Survey provides the only opportunity in the coming decades to grow this catalog by order(s) of magnitude. This can be achieved if 1) Roman's astrometric potential is fully realized in the observation strategy and software pipelines, 2) Roman's observational gaps of the Bulge are minimized, and 3) observations with ground-based facilities are taken of the Bulge to fill in gaps during non-Bulge seasons. A large sample of isolated BHs will enable a broad range of astrophysical questions to be answered, such as massive stellar evolution, origin of gravitational wave sources, supernova physics, and the growth of supermassive BHs, maximizing Roman's scientific return.