Diffuse gamma-ray emission from galactic pulsars

Abstract

Millisecond Pulsars are second most abundant source population discovered by the Fermi-LAT. They might contribute non-negligibly to the diffuse emission measured at high latitudes by Fermi-LAT, the IDGRB. Gamma-ray sources also contribute to the anisotropy of the IDGRB measured on small scales by Fermi-LAT. We aim to assess the contribution of the unresolved counterpart of the detected MSPs population to the IDGRB and the maximal fraction of the measured anisotropy produced by this source class. We model the MSPs spatial distribution in the Galaxy and the gamma-ray emission parameters by considering radio and gamma-ray observational constraints. By simulating a large number of MSPs populations, we compute the average diffuse emission and the anisotropy 1-sigma upper limit. The emission from unresolved MSPs at 2 GeV, where the peak of the spectrum is located, is at most 0.9% of the measured IDGRB above 10 degrees in latitude. The 1-sigma upper limit on the angular power for unresolved MSP sources turns out to be about a factor of 60 smaller than Fermi-LAT measurements above 30 degrees. Our results indicate that this galactic source class represents a negligible contributor to the high-latitude gamma-ray sky and confirm that most of the intensity and geometrical properties of the measured diffuse emission are imputable to other extragalactic source classes. Nevertheless, given the MSP distribution, we expect them to contribute significantly to the gamma-ray diffuse emission at low latitudes. Since, along the galactic disk, the population of young Pulsars overcomes in number the one of MSPs, we compute the gamma-ray emission from the whole population of unresolved Pulsars in two low-latitude regions: the inner Galaxy and the galactic center.

19 pages, 26 figures. It matches the published version, minor changes only

References in corpus (13)

• The ATNF Pulsar Catalogue
• Observations of the Crab Nebula with H.E.S.S
• The Parkes multibeam pulsar survey: VI. Discovery and timing of 142 pulsars and a Galactic population analysis
• The Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived From First-Year Fermi Large Area Telescope Data
• The Fermi-LAT high-latitude Survey: Source Count Distributions and the Origin of the Extragalactic Diffuse Background
• Star-forming galaxies as the origin of diffuse high-energy backgrounds: Gamma-ray and neutrino connections, and implications for starburst history
• Population synthesis of radio and gamma-ray millisecond pulsars from the Galactic disk
• Constraints on the Emission Geometries and Spin Evolution of Gamma-ray Millisecond Pulsars
• Gamma rays from clusters of galaxies
• Millisecond pulsar interpretation of the Galactic center gamma-ray excess
• Joint anisotropy and source count constraints on the contribution of blazars to the diffuse gamma-ray background
• Pulsed Gamma-rays from the millisecond pulsar J0030+0451 with the Fermi Large Area Telescope
• High-Energy Emission of the First Millisecond Pulsar

Cited by in corpus (13)

• Background model systematics for the Fermi GeV excess
• A Tale of Tails: Dark Matter Interpretations of the Fermi GeV Excess in Light of Background Model Systematics
• The Origin of the Extragalactic Gamma-Ray Background and Implications for Dark-Matter Annihilation
• GeV excess in the Milky Way: The Role of Diffuse Galactic gamma ray Emission template
• Millisecond pulsars and the Galactic Center gamma-ray excess: the importance of luminosity function and secondary emission
• Gamma-ray sky points to radial gradients in cosmic-ray transport
• Updated cosmic-ray and radio constraints on light dark matter: Implications for the GeV gamma-ray excess at the Galactic center
• Antiproton constraints on the GeV gamma-ray excess: a comprehensive analysis
• Distinguishing Dark Matter from Unresolved Point Sources in the Inner Galaxy with Photon Statistics
• Testing the millisecond pulsar scenario of the Galactic center gamma-ray excess with very high energy gamma-rays
• Angular Power Spectra with Finite Counts
• Can galactic dark matter substructure contribute to the cosmic gamma-ray anisotropy?
• Gamma rays from Galactic pulsars