Constraining the nature of the Galactic center black hole Sgr A* with present and future observations

TL;DR

This paper explores methods to use observations of Sgr A*'s surroundings to determine its spin and test whether it is a black hole or a different compact object, advancing our understanding of strong gravity.

Contribution

It introduces three novel observational approaches to constrain Sgr A*'s properties and test the fundamental nature of the object at our galaxy's center.

Findings

Proposed three observational methods for probing Sgr A*

Demonstrated potential to constrain black hole spin

Enabled testing of the black hole hypothesis

Abstract

The Galactic center is an ideal laboratory to study strong-field general relativistic phenomena, as the supermassive black hole Sgr A* has the biggest angular Schwarzschild radius among all black holes. This article presents three different ways of using the immediate surroundings of Sgr A* as a probe in order to either constrain its spin, or even test the very nature of this compact object.