XMM Studies of a Millisecond Pulsar Coincident with a Fermi LAT Source

We propose to use XMMNewton to search for Xray pulsations in the counterpartto a newlydiscovered Fermi LAT Source. This source is a binary millisecondpulsar. The radio observations have also found the orbital solution proving thecompanion has very low mass, suggesting a black widow system. A Chandra image ofthe LAT field provides possible Xray counterparts. The radio position suggestsone of these is the best candidate although it is not yet definitive. Specificobjectives of the XMM search are (1) detect Xray pulsations, get pulsed fluxand light curve, (2) determine offpulse flux, again to compare with otherwavelengths; (3) spectrum of the source as a function of orbital phase. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]