Search for the SNR signatures in W50 that harbors the microquasar SS 433

It is a debated topic whether the very massive stars end their lives withsupernova explosions or not. Finding a supernova remnant (SNR) hosting a blackhole can provide direct evidence for the former scenario. SS 433, in the giantbubble W50, is a paradigmatic microquasar containing a virgul16Msun black hole. ItsSNR has not been firmly established, as its energetic jets are considered as themajor source to produce W50. The ROSAT image shows thermal structures in thenorth of W50, which are far from the jet precession cone. We propose 72 ks XMMNewton observation toward the northern shell of W50, aiming to find signaturesof a SNR and to study the explosion mechanism of SS433 s supernova. A nondetection would provide evidence that multiple episodes of jets in the past. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]