Diffuse X-Ray Emission in the Sagittarius C Complex

Abstract The Sagittarius C (Sgr C) complex, located on the western edge of the central molecular zone (CMZ), hosts a mixture of star-forming and nonthermal activity whose X-ray properties remain poorly understood. Using deep archival Chandra and XMM-Newton observations, we resolve the diffuse X-ray emission in Sgr C into two components: an H ii region coincident with the radio peak and a brighter diffuse feature located to its southwest. Spatially resolved spectroscopy reveals the presence of a soft ( kT ≤ 1 keV) plasma with metal abundances consistent with the elevated metallicity expected in the CMZ in both regions, along with a harder (∼8 keV) thermal component within the H ii region. The observed diffuse X-ray emission and its association with an expanding [C ii ] shell suggest that the hot gas may originate from a young supernova remnant (SNR) embedded in the H ii region. Under this interpretation, the inferred shock velocity (∼800 km s −1 ) and SNR age (≥1.7 kyr) are consistent with a core-collapse SNR in the Galactic center. These results reveal Sgr C as a potential host of an SNR and highlight the complex interplay between massive-star feedback, magnetic fields, and molecular gas in the CMZ.