How to create Sgr A East

Abstract

Context. 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. Aims. We aspire to create a simple model of a supernova explosion that reproduces the shape, size, and location of Sgr A East. Methods. 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. Results. 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.