2014/07/21 by Ilias Cholis, Dan Hooper, Cholis, Ilias +3 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #FOS: Physical sciences #Gamma-ray bursts and supernovae #Geophysics and Gravity Measurements #High Energy Astrophysical Phenomena (astro-ph.HE) #High Energy Physics - Phenomenology (hep-ph) #Nuclear Physics and Applications #Pulsars and Gravitational Waves Research #Solar and Stellar Astrophysics (astro-ph.SR)
paper · pdf · doi:10.48550/arxiv.1407.5583
openalex publication_date 2014/07/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this article, we revisit the gamma-ray emission observed from millisecond\npulsars and globular clusters. Based on 5.6 years of data from the Fermi\nGamma-Ray Space Telescope, we report gamma-ray spectra for 61 millisecond\npulsars, finding most to be well fit by a power-law with an exponential cutoff,\nproducing to a spectral peak near ~1-2 GeV (in E2 dN/dE units).\nAdditionally, while most globular clusters exhibit a similar spectral shape, we\nidentify a few with significantly softer spectra. We also determine the\ngamma-ray luminosity function of millisecond pulsars using the population found\nin the nearby field of the Milky Way, and within the globular cluster 47\nTucanae. We find that the gamma-ray emission observed from globular clusters is\ndominated by a relatively small number of bright millisecond pulsars, and that\nlow-luminosity pulsars account for only a small fraction of the total flux. Our\nresults also suggest that the gamma-ray emission from millisecond pulsars is\nmore isotropic and less strongly beamed than the emission at X-ray wavelengths.\nFurthermore, the observed distribution of apparent gamma-ray efficiencies\nprovides support for the slot gap or the outer gap models over those in which\nthe gamma-ray emission originates from regions close to the neutron star's\nmagnetic poles (polar cap models).\n