Population Syntheses of Millisecond Pulsars from the Galactic Disk and Bulge

Abstract

We present the results of a population synthesis of radio and γ -ray millisecond pulsars (MSPs) from the galactic disk (GD). Using 92 radio MSPs detected in 13 radio surveys and 54 Fermi MSPs detected as point sources in the first point source catalog, we establish six free parameters corresponding to the overall factor and the exponents of the period and period derivative dependence for each of the radio and γ -ray empirical luminosity models. We test three high-energy emission models described by the two-pole caustic slot-gap, outer-gap, and pair-starved polar-cap geometries. The simulated distributions of pulsar properties adequately describe the distributions of detected MSPs from the GD. We explore the γ -ray emission from groups of MSPs in globular clusters and in the galactic bulge. The simulation predicts reasonable numbers of Fermi MSPs detected in the other point source catalogs and anticipates a bright future for Fermi observations of MSPs, expecting a total of ≈170 MSP detections from the GD within 10 years. Our numbers of simulated MSPs in globular clusters are in agreement with those derived from Fermi detections. The simulation predicts that about 11,000 MSPs in the galactic bulge are required to explain the γ -ray galactic center excess.