Millisecond Pulsars, Positrons and the Galactic Bulge

Abstract:

Rotation-powered pulsars that spin at millisecond periods are prevalent in the Galaxy as radio, X-ray and gamma-ray pulsars. Fermi has discovered a population of gamma-ray millisecond pulsars (MSPs) in the disk and in globular clusters.  Pulsars have been invoked to explain the local cosmic-ray positron excess, seen by AMS2, as well as the gamma-ray excess at the Galactic center seen by Fermi.  I will discuss population synthesis simulations of radio and gamma-ray MSPs and the question of whether MSPs could account for the Galactic bulge excess.  A population of MSP binaries thought to contain intra-binary shocks that accelerate positrons could also be contributing to the local positron excess.