The X-ray counterpart of the energetic msec pulsar binary PSRJ1431-4715

Millisecond pulsars have boosted in number thanks to the detection of highenergy GeV emission by Fermi. Those in compact binaries with nondegeneratecompanions,the redbacks (RB), challenge the evolutionary link between neutronstar low mass Xray binary and rotationpowered radio pulsars with 3 systemsfound to transit between the two stages.A new gammaray source has been recentlyidentified with the energetic radio pulsar PSRJ14314715 in a RB sharingsimilarities with the 3 transitional pulsars. We propose to study for the firsttime the Xray emission arising from an intrabinary shock between the powerfulpulsar and companion winds to determine the energy budget and the amount ofirradiation of the companion, a key parameter to understand how RBs undergo transitions. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]