XMM-Newton observation of the Galactic supernova remnant W51C (G49.1–0.1)

Context. The supernova remnant (SNR) W51C is a Galactic object located in a strongly inhomogeneous interstellar medium with signs of an interaction of the SNR blast wave with dense molecular gas. Aims. Diffuse X-ray emission from the interior of the SNR can reveal element abundances in the different emission regions and shed light on the type of supernova (SN) explosion and its progenitor. The hard X-ray emission helps to identify possible candidates for a pulsar formed in the SN explosion and for its pulsar wind nebula (PWN). Methods. We have analysed X-ray data obtained with XMM-Newton. Spectral analyses in selected regions were performed. Results. Ejecta emission in the bright western part of the SNR, located next to a complex of dense molecular gas, was confirmed. The Ne and Mg abundances suggest a massive progenitor with a mass of >20 M� . Two extended regions emitting hard X-rays were identified (corresponding to the known sources [KLS2002] HX3 west and CXO J192318.5+140305 discovered with ASCA and Chandra, respectively), each of which has an additional point source inside and shows a power-law spectrum with Γ ≈ 1.8. Based on their X-ray emission, both sources can be classified as PWN candidates.