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Fermi LAT detection of a GeV flare from blazar TXS 0059+581

ATel #3864; D. Donato (CRESST/UMCP/GSFC), on behalf of the Fermi Large Area Telescope Collaboration
on 13 Jan 2012; 15:29 UT
Credential Certification: Davide Donato (davide.donato-1@nasa.gov)

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

Referred to by ATel #: 8981

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed gamma-ray flaring activity from a source positionally consistent with the flat spectrum radio quasar TXS 0059+581, also known as 2FGL J0102.7+5827 (Abdo et al. 2011, ApJS, submitted, arXiv:1108.1435) at position (J2000.0) R.A. 01h 02m 45.7623s, Dec. +58d 24m 11.136s (Johnston et al. 1995, AJ, 110, 880).

This blazar is at low Galactic latitude (b=-4 deg) and has a measured redshift of 0.644 (Sowards-Emmerd et al. 2005, ApJ, 626, 95). It has a radio jet that is monitored by the MOJAVE program (Lister & Homan, 2005, AJ, 130, 1389).

Preliminary analysis indicates that on 2012 January 11, TXS 0059+581 was in a high state with an average daily gamma-ray flux (E>100MeV) of (1.0 +/- 0.2) x 10^-6 photons cm^-2 s^-1 (statistical uncertainty only), about 20 times greater than the average flux reported in the second Fermi LAT catalog (2FGL).

Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. In consideration of the ongoing activity of this source we encourage multiwavelength observations. For this source the Fermi LAT contact person 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.