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

Journal Article · Sat May 10 00:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/786/2/109· OSTI ID:22356919

Singal, J. ^[1]; Ko, A. ^[2]

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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)

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.

• OSTI ID: 22356919
• Journal Information: Astrophysical Journal, Vol. 786, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

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