Gamma-Ray Emission from the Broad-Line Radio Galaxy 3C111

Abstract

The broad-line radio galaxy 3C111 has been suggested as the counterpart of the gamma-ray source 3EGJ0416+3650. While 3C111 meets most of the criteria for a high-probability identification, like a bright flat-spectrum radio core and a blazar-like broadband SED, in the Third EGRET Catalog, the large positional offset of about 1.5 degrees put 3C111 outside the 99% probability region for 3EGJ0416+3650, making this association questionable. We present a re-analysis of all available data for 3C111 from the EGRET archives, resulting in probable detection of high-energy gamma-ray emission above 1000MeV from a position close to the nominal position of 3C111, in two separate viewing periods (VPs), at a 3-sigma level in each. A new source, GROJ0426+3747, appears to be present nearby. For >100MeV, one source seems to account for most of the EGRET-detected emission of 3EGJ0416+3650. A follow-up Swift UVOT/XRT observation reveals one moderately bright X-ray source in the error box of 3EGJ0416+3650, but because of the large EGRET position uncertainty, it is not certain that the X-ray and gamma-ray sources are associated. Another Swift observation, of GROJ0426+3747, detected no X-ray source nearby.

arXiv commentaccepted for publication in ApJ; needs aastex.cls

References in corpus (9)

• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• Structured jets in TeV BL Lac objects and radiogalaxies
• Swift BAT Survey of AGN
• Superluminal Radio Features in the M87 Jet and the Site of Flaring TeV Gamma-ray Emission
• The First INTEGRAL AGN Catalog
• GeV emission from the nearby radio galaxy Centaurus A
• Is the EGRET source 3EG J1621+8203 the radio galaxy NGC 6251?
• The Trails of Superluminal Jet Components in 3C111
• Is 3C111, an apparently normal radio galaxy, the counterpart of 3EG J0416+3650?

Cited by in corpus (19)

• The Second Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• The Third Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• Bright AGN Source List from the First Three Months of the Fermi Large Area Telescope All-Sky Survey
• Fermi Discovery of Gamma-Ray Emission from NGC 1275
• Fermi Large Area Telescope Gamma-Ray Detection of the Radio Galaxy M87
• Fermi Large Area Telescope Observations of Misaligned AGN
• Fermi Large Area Telescope View of the Core of the Radio Galaxy Centaurus A
• Connection between the Accretion Disk and Jet in the Radio Galaxy 3C 111
• Broad Line Radio Galaxies Observed with Fermi-LAT: The Origin of the GeV Gamma-Ray Emission
• The gamma-ray emission region in the FRII Radio Galaxy 3C 111
• The Suzaku view of 3C 382
• VHE Gamma-Ray Induced Pair Cascades in the Radiation Fields of Dust Tori of AGN: Application to Cen A
• VLBA polarimetric monitoring of 3C 111
• The High Energy view of the Broad Line Radio Galaxy 3C 111
• Unraveling the Nature of Unidentified High Galactic Latitude Fermi/LAT Gamma-ray Sources with Suzaku
• VHE Gamma-Ray Induced Pair Cascades in Blazars and Radio Galaxies: Application to NGC 1275
• The nature of the multi-wavelength emission of 3C 111
• Sub-milliarcsecond imaging of a bright flare and ejection event in the extragalactic jet 3C 111
• Gamma-ray emission in radio galaxies, from MeV to TeV