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arXiv · 1109.2734

Fermi/LAT Observations of Swift/BAT Seyferts: on the Contribution of Radio-quiet AGN to the Extragalactic Gamma-ray Background

Stacy H. Teng·Richard F. Mushotzky·Rita M. Sambruna·David S. Davis·Christopher S. Reynolds
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Abstract

We present the analysis of 2.1 years of Fermi/LAT data on 491 Seyfert galaxies detected by the Swift/BAT survey. Only the two nearest objects, NGC 1068 and NGC 4945, which were identified in the Fermi First-year Catalog, are detected. Using the Swift/BAT and radio 20 cm fluxes, we define a new radio-loudness parameter $R_{X, BAT}$ where radio loud objects have $\log R_{X, BAT} > - 4.7$. Based on this parameter, only radio loud sources are detected by Fermi/LAT. An upper limit to the flux of the undetected sources is derived to be $\sim 2 \times 10^{-11}$ photons cm$^{-2}$ s$^{-1}$, approximately seven times lower than the observed flux of NGC 1068. Assuming a median redshift of 0.031, this implies an upper limit to the $γ$-ray (1--100 GeV) luminosity of $\lesssim 3 \times 10^{41}$ erg s$^{-1}$. In addition, we identified 120 new Fermi/LAT sources near the Swift/BAT Seyferts with significant Fermi/LAT detections. A majority of these objects do not have \bat counterparts, but their possible optical counterparts include blazars, FSRQs, and quasars.

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Stacy H. Teng, Richard F. Mushotzky, Rita M. Sambruna, David S. Davis, Christopher S. Reynolds. 2011-09-13. Fermi/LAT Observations of Swift/BAT Seyferts: on the Contribution of Radio-quiet AGN to the Extragalactic Gamma-ray Background. https://doi.org/10.1088/0004-637x%2F742%2F2%2F66

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