Binary Pulsar Shock Emissions as Galactic Gamma-ray Sources

We address several issues regarding the interpretation of galactic -ray sources. We consider powerful pulsars in binaries producing X-ray and gamma-ray unpulsed emission from the shock interaction of relativistic pulsar winds with circumbinary material. Nebular mass out ows from companion stars of binary pulsars can provide the right calorimeters to transform a fraction of the electromagnetic and kinetic energy of pulsar winds into high energy radiation. We discuss the physics of interaction of relativistic pulsar winds with gaseous material and show that the conditions in pulsar binary systems might be ideal to constrain shock acceleration mechanisms and pulsar wind composition and structure. We brie y discuss the example of the 47 ms pulsar PSR 1259-63 orbiting around a massive Be star companion and monitored by X-ray and gamma-ray instruments during its recent periastron passage. In addition to young pulsars in massive binaries, also a class of recycled millisecond pulsars in low-mass binaries can be interesting high energy emitters.