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Title: Gamma-ray luminosity and photon index evolution of FSRQ blazars and contribution to the gamma-ray background

We present the redshift evolutions and distributions of the gamma-ray luminosity and photon spectral index of flat spectrum radio quasar (FSRQ) type blazars, using non-parametric methods to obtain the evolutions and distributions directly from the data. The sample we use for analysis consists of almost all FSRQs observed with a greater than approximately 7σ detection threshold in the first-year catalog of the Fermi Gamma-ray Space Telescope's Large Area Telescope, with redshifts as determined from optical spectroscopy by Shaw et al. We find that FSQRs undergo rapid gamma-ray luminosity evolution, but negligible photon index evolution, with redshift. With these evolutions accounted for we determine the density evolution and luminosity function of FSRQs and calculate their total contribution to the extragalactic gamma-ray background radiation, resolved and unresolved, which is found to be 16(+10/–4)%, in agreement with previous studies.
Authors:
 [1] ;  [2] ;  [3]
  1. Physics Department, University of Richmond, 28 Westhampton Way, Richmond, VA 23173 (United States)
  2. Department of Physics, Masacusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307 (United States)
  3. Kavli Institute for Particle Astrophysics and Cosmology, Departments of Physics and Applied Physics, Stanford University, 382 Via Pueblo Mall, Stanford, CA 94305-4060 (United States)
Publication Date:
OSTI Identifier:
22356919
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 786; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APPROXIMATIONS; BACKGROUND RADIATION; CATALOGS; DATA ANALYSIS; DETECTION; DISTRIBUTION; EVOLUTION; GALAXIES; GAMMA RADIATION; LUMINOSITY; PHOTONS; QUASARS; RED SHIFT; SPACE; SPECTRA; SPECTROSCOPY; TELESCOPES