A population of gamma-ray millisecond pulsars seen with the Fermi large area telescope

Pulsarsare born with subsecond spin periods and slow by electromagnetic brakingfor several tens of millions of years, when detectable radiation ceases. A second life can occur for neutron starsin binary systems. They can acquire mass and angular momentum from their companions, to be spun up to millisecondperiods and begin radiating again. We searched Fermi Large Area Telescope data for pulsations from all known millisecond pulsars(MSPs) outside of globular clusters, using rotation parameters from radio telescopes. Strong gamma-raypulsations were detected for eight MSPs. The gamma-raypulse profiles and spectral properties resemble those of young gamma-ray pulsars. The basic emission mechanism seems to be the same for MSPs and young pulsars, with the emission originating in regions far from the neutron starsurface.