Stellar-Mass Black Holes

TL;DR

This review discusses the physics, detection methods, and astrophysical significance of stellar-mass black holes, highlighting current knowledge, challenges, and open questions in the field.

Contribution

It provides a comprehensive overview of stellar-mass black holes, including their formation, detection, and the open issues in understanding these objects.

Findings

Fewer than 100 stellar-mass black holes are known in our Galaxy.

Most known black holes are detected via gravitational waves in recent years.

The article discusses potential interstellar missions to study black holes.

Abstract

Stellar-mass black holes ($3$ $M_\odot \lesssim M_{\rm BH} \lesssim 150$ $M_\odot$) are the natural product of the evolution of heavy stars ($M_{\rm star} \gtrsim 20$ $M_\odot$). In our Galaxy, we expect $10^8$-$10^9$ stellar-mass black holes formed from the gravitational collapse of heavy stars, but currently we know fewer than 100 objects. We also know $\sim 100$ stellar-mass black holes in other galaxies, most of them discovered by gravitational wave observatories in the past 10 years. The detection of black holes is indeed extremely challenging and possible only in very special cases. This article is a short review on the physics and astrophysics of stellar-mass black holes, including Galactic and extragalactic black holes in X-ray binaries, black holes in astrometric binaries, isolated black holes, and black holes in compact binaries. The article also addresses some important open issues and introduces the idea of a possible interstellar mission to the closest black hole.