Isolating Sgr A East: The First Uncontaminated X-Ray Maps of a Galactic Center Supernova Remnant

Abstract The central few parsecs of the Milky Way host a complex X-ray-emitting environment in which several extended plasma components are blended along the line of sight, complicating attempts to measure the intrinsic properties of individual components. In particular, the supernova remnant (SNR) Sgr A East is strongly confused with the stellar wind-fed plasma associated with Sagittarius A* and the surrounding nuclear environment. Here we apply Poissonian Generalized Morphological Component Analysis to deep, stacked Chandra ACIS-I observations of the Galactic center to disentangle these overlapping X-ray components. By comparing the separated X-ray components with multiwavelength data, we identify the location of the reflected shock in Sgr A East and construct spatially resolved maps of Fe and S/Ar/Ca emission. The Fe emission is centrally concentrated, consistent with the properties of mixed-morphology supernova remnants. Separating the SNR emission from the shocked wind plasma around Sgr A* allows us to recover uncontaminated SNR properties and improve the robustness of the derived parameters. Spectral modeling of the isolated Sgr A East component reveals a lower ionization age and a higher electron density than previously reported, indicating strong interaction with dense surrounding material.