IDENTIFYING THE SOURCES OF X-RAY EMISSION FROM THE BLACK WIDOW PULSAR

We propose to observe the original eclipsing binary millisecond radio pulsarB1957+20 at high time resolution in order to determine the origins of the knownXray flux from the system. These observations will detect the pulsedmagnetospheric emission that is certainly produced by this energetic pulsar andallow us to determine the fraction of the total Xray flux that it represents.Additionally, the detection of modulation of the pulsed and/or unpulsed Xrayflux as a function of the 9 hr orbital period will enable us to determine what(if any) emission results from the intrabinary shock (from the collision ofpulsar and companion winds) and/or the pulsar bow shock (from the interaction ofthe pulsar wind with the ISM). truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]