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Fermi LAT detection of a GeV flare from the Radio-Loud Narrow-Line Sy1 SBS 0846+513

ATel #3452; D. Donato (CRESST/UMCP/GSFC), J. S. Perkins (CRESST/UMBC/GSFC), on behalf of the Fermi Large Area Telescope Collaboration
on 24 Jun 2011; 16:13 UT
Credential Certification: Davide Donato (davide.donato-1@nasa.gov)

Subjects: Gamma Ray, >GeV, AGN, Blazar, Transient

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed an increasing gamma-ray flux from a source positionally consistent with SBS 0846+513 (RA=08h49m57.9768s, Dec=+51d08'29.023", J2000, Kovalev et al. 2007, AJ, 133, 1236), a z=0.583715 radio-loud narrow line Seyfert 1 galaxy (Zhou et al. 2005 ChJAA, 5, 41).

Preliminary analysis indicates that on June 21, 2011 the source was in a high state with a gamma-ray flux (E>100MeV) of (0.8 +/-0.2) x10^-6 photons cm^-2 s^-1. During the first 2 years of the Fermi mission, this source was not detected, yielding an upper limit on the flux of 4.0 x10^-9 photons cm^-2 s^-1. In the last 11 months this source has brightened to an average flux of (5.8 +/-0.7) x10^-8 photons cm^-2 s^-1. Recently on June 17, SBS 0846+513 was detected in a single 24 hr timeframe with a gamma-ray flux of (0.4 +/-0.2) x10^-6 photons cm^-2 s^-1 (all errors are statistical only).

Since Fermi operates in an all-sky scanning mode, regular monitoring of this source will continue. In consideration of the ongoing activity of this source we strongly encourage multiwavelength observations. The Fermi LAT contact person for this source is D. Donato (donato@milkyway.gsfc.nasa.gov).

The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.

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