A Chandra View of Diffuse X-Ray Emission in the Central 20 Parsecs of the Galaxy

Abstract

Over the last three years, the Galactic center region has been monitored with a series of Chandra/ACIS observations. Besides the target object Sgr A*, the surrounding diffuse X-ray emission has been detected within the 17′ × 17′ field of view. As of 2002 June, combining all 12 GTO and GO observations, the total effective exposure reaches ∼ 590 ks, which reveals the detail structure of the faint filamentary diffuse X-ray emission with significant photon statistics. We here present preliminary results from the imaging/spectral analyses of these data. The “true-color” X-ray image and the equivalent width (EW) images for the detected elemental species of the Galactic center region indicate that the diffuse X-ray features have complex spatiospectral structures. We detect strong enhancements of He-like Fe within the 1.3′ diameter circular region in the immediate east of Sgr A*, which is most likely emission from the highly ionized Fe associated with the supernova remnant Sgr A East. Enhancements of the low ionization state Fe and highly ionized S and Si EWs in the northeast of Sgr A* may be interpreted as irradiation of photons from external X-ray sources and/or emission from bombardments of high energy particles such as unresolved SN ejecta.