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Fermi LAT detection of renewed gamma-ray activity from blazar 4C +71.07 (S5 0836+71)

ATel #3831; Stefano Ciprini (ASI Science Data Center, Italy); Michael Dutka (Catholic University of America, Washington, DC, USA), on behalf of the Fermi Large Area Telescope Collaboration
on 28 Dec 2011; 10:55 UT
Credential Certification: Stefano Ciprini (stefano.ciprini@pg.infn.it)

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

Referred to by ATel #: 3835, 7870, 8223, 8266

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed renewed flaring activity from a source positionally consistent with the flat spectrum radio quasar 4C +71.07, also known as S5 0836+71, 1ES 0836+710, 3EG J0845+7049, 1FGL J0842.2+7054, 2FGL J0841.6+7052 (Abdo et al. 2011, submitted to ApJS, arXiv:1108.1435) with VLBI coordinates, (J2000.0), R.A.: 08h 41m 24.3652s, Dec.: +70d 53m 42.173s (Johnston et al. 1995, AJ, 110, 880) and redshift z=2.218 (McIntosh et al. 1999, ApJ, 514, 40). This optically bright and MeV-peaked gamma-ray blazar was seen in a flaring state for the first time by the LAT at beginning of April 2011 (ATel#3260).

Preliminary analysis indicates that 4C +71.07 (S5 0836+71) on 2011, December 25 was in a high state with an average daily gamma-ray flux (E>100MeV) of (1.7 +/- 0.2) x 10^-6 photons cm^-2 s^-1 (statistical uncertainty only), about 26 times greater than the average flux reported in the second Fermi-LAT source 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 persons are K. Sokolovsky (ksokolov@mpifr-bonn.mpg.de) and D.J. Thompson (David.J.Thompson@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.