The Milky Way's nuclear star cluster and massive black hole

TL;DR

This paper reviews our detailed understanding of the Milky Way's central black hole, Sagittarius A*, and the surrounding nuclear star cluster, emphasizing observational challenges and key research areas due to our proximity.

Contribution

It provides a concise overview of current knowledge, observational challenges, and key research questions regarding the Milky Way's nucleus and black hole.

Findings

Precise measurements of Sagittarius A*

Detailed study of nuclear star cluster dynamics

Identification of observational limitations

Abstract

Because of its nearness to Earth, the centre of the Milky Way is the only galaxy nucleus in which we can study the characteristics, distribution, kinematics, and dynamics of the stars on milli-parsec scales. We have accurate and precise measurements of the Galactic centre's central black hole, Sagittarius A*, and can study its interaction with the surrounding nuclear star cluster in detail. This contribution aims at providing a concise overview of our current knowledge about the Milky Way's central black hole and nuclear star cluster, at highlighting the observational challenges and limitations, and at discussing some of the current key areas of investigation.