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Fermi LAT detection of a gamma-ray flare from CGRaBS J0211+1051

ATel #3120; F. D'Ammando (INAF-IASF Palermo) on behalf of the Fermi Large Area Telescope Collaboration
on 25 Jan 2011; 18:13 UT
Credential Certification: Filippo D'Ammando (filippo.dammando@iasf-roma.inaf.it)

Subjects: >GeV, AGN, Blazar

Referred to by ATel #: 3127, 3129, 3131, 3133, 3134, 3136

The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope detected on 23 January 2011 increasing gamma-ray activity from a source positionally consistent with the BL Lac object CGRaBS J0211+1051 (also known as MG1 J021114+1051, and 1FGL J0211.2+1049, Abdo et al. 2010, ApJS, 188, 405; R.A.= 02:11:13.177, Dec.=+10:51:34.798, J2000.0; Beasley et al. 2002, ApJS, 141, 13). Recently the redshift of the object was estimated from observation of its host galaxy as z = 0.20+/-0.05 (Meisner and Romani 2010, ApJ, 714, 14).

Preliminary analysis indicates that CGRaBS J0211+1051 on 23 January 2011 was in a high state, with a daily gamma-ray flux (E > 100 MeV) of (1.0 +/- 0.3) x 10^-6 ph cm^-2 s^-1 (statistical uncertainty only), which represents an increase of a factor of 25 with respect to the average source flux observed in the first eleven months of Fermi observations (Abdo et al. 2010, ApJS, 188, 405).

Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. In consideration of the activity of this source we strongly encourage multiwavelength observations. The Fermi LAT contact person for this source is F. D'Ammando (dammando@ifc.inaf.it).

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.