Search For Gamma-Ray Emission From X-Ray-Selected Seyfert Galaxies With Fermi -LAT
Journal Article
·
· The Astrophysical Journal
- Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); et al.
We report on a systematic investigation of the γ-ray properties of 120 hard Xray– selected Seyfert galaxies classified as ‘radio-quiet’ objects, utilizing the threeyear accumulation of Fermi–LAT data. Our sample of Seyfert galaxies is selected using the Swift–BAT 58-month catalog, restricting the analysis to the bright sources with average hard X-ray fluxes F14-195 keV ≥ 2.5 × 10-11 erg cm-2 s-1 at high Galactic latitudes (|b| > 10°). In order to remove ‘radio-loud’ objects from the sample, we use the ‘hard X-ray radio loudness parameter’, RrX , defined as the ratio of the total 1.4 GHz radio to 14 - 195 keV hard X-ray energy fluxes. Among 120 X-ray bright Seyfert galaxies with RrX < 10-4, we did not find a statistically significant γ-ray excess (TS > 25) positionally coincident with any target Seyferts, with possible exceptions of ESO 323–G077 and NGC 6814. The mean value of the 95% confidence level γ-ray upper limit for the integrated photon flux above 100 MeV from the analyzed Seyferts is ≃ 4×10-9 ph cm-2 s-1 , and the upper limits derived for several objects reach ≃ 1 × 10-9 ph cm-2 s-1 . Our results indicate that no prominent γ-ray emission component related to active galactic nucleus activity is present in the spectra of Seyferts around GeV energies. The Fermi–LAT upper limits derived for our sample probe the ratio of γ-ray to X-ray luminosities L /LX < 0.1, and even < 0.01 in some cases. The obtained results impose novel constraints on the models for high energy radiation of ‘radio-quiet’ Seyfert galaxies.
- Research Organization:
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE
- Contributing Organization:
- Fermi LAT Collaboration
- Grant/Contract Number:
- AC02-76SF00515
- OSTI ID:
- 1356759
- Alternate ID(s):
- OSTI ID: 22016216
- Journal Information:
- The Astrophysical Journal, Journal Name: The Astrophysical Journal Journal Issue: 2 Vol. 747; ISSN 0004-637X
- Publisher:
- Institute of Physics (IOP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
SEARCH FOR GAMMA-RAY EMISSION FROM X-RAY-SELECTED SEYFERT GALAXIES WITH FERMI-LAT
FERMI/LAT OBSERVATIONS OF SWIFT/BAT SEYFERT GALAXIES: ON THE CONTRIBUTION OF RADIO-QUIET ACTIVE GALACTIC NUCLEI TO THE EXTRAGALACTIC {gamma}-RAY BACKGROUND
Diffuse γ-ray emission from misaligned active galactic nuclei
Journal Article
·
Fri Mar 09 23:00:00 EST 2012
· Astrophysical Journal
·
OSTI ID:22016216
FERMI/LAT OBSERVATIONS OF SWIFT/BAT SEYFERT GALAXIES: ON THE CONTRIBUTION OF RADIO-QUIET ACTIVE GALACTIC NUCLEI TO THE EXTRAGALACTIC {gamma}-RAY BACKGROUND
Journal Article
·
Wed Nov 30 23:00:00 EST 2011
· Astrophysical Journal
·
OSTI ID:22004651
Diffuse γ-ray emission from misaligned active galactic nuclei
Journal Article
·
Thu Jan 09 23:00:00 EST 2014
· Astrophysical Journal
·
OSTI ID:22348228