How to create Sgr A East: Where did the supernova explode?

TL;DR

This paper models the supernova remnant Sgr A East using hydrodynamical simulations to estimate its age and explosion site, suggesting it is about 10,000 years old and exploded near the Galactic centre.

Contribution

It introduces a simplified hydrodynamical model that reproduces Sgr A East's shape, size, and location, providing new estimates for its age and explosion site.

Findings

Sgr A East is likely around 10 kyr old.

The supernova exploded approximately 3.5 pc from the Galactic centre.

Suitable models exclude ages younger than 5 kyr.

Abstract

Sgr A East is the supernova remnant closest to the centre of the Milky Way. Its age has been estimated to be either very young, around 1-2 kyr, or about 10 kyr, and its exact origin remains unclear. We aspire to create a simple model of a supernova explosion that reproduces the shape, size, and location of Sgr A East. Using a simplified hydrodynamical code, we simulated the evolution of a supernova remnant in the medium around the Galactic centre. The latter consists of a nearby massive molecular cloud with which Sgr A East is known to be interacting and a wind from the nuclear star cluster. Our preferred models of the Sgr A East remnant are compatible with an age of around 10 kyr. We also find suitable solutions for older ages, but not for ages younger than 5 kyr. Our simulations predict that the supernova exploded at a distance of about 3.5 pc from the Galactic centre, below the Galactic plane, slightly eastwards from the centre and 3 pc behind it.