The Structure of the Bow Shock Nebula Surrounding PSR B1853+01 in the SNR W44

The pulsar wind bow shock nebula surrounding PSR B1853+01, embedded within theSNR W44, is the oldest known wind nebula associated with an active pulsar.Chandra observations have shown that the Xray morphology is that of anasymmetric nebula trailing behind the pulsar.s apparent motion direction, with asmaller extent than the radio. A recent, deep Chandra image suggests an extendedregion of emission preceding the pulsar. The verification of the nature of thisemission as nonthermal and associated with the pulsar has strong implicationsfor our understanding of pulsar bow shock nebulae. We propose a 75 ks EPICobservation of this intriguing object, exploiting XMMNewton.s unique surfacebrightness sensitivity above 3 keV to establish the nature of the emission. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]