Fermi LAT detection of a gamma-ray flare from CGRaBS J1849+6705
ATel #3478; F. D'Ammando (INAF-IASF Palermo and CIFS) on behalf of the Fermi Large Area Telescope Collaboration
on 8 Jul 2011; 08:29 UT
Credential Certification: Filippo D'Ammando (filippo.dammando@iasf-roma.inaf.it)
Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Blazar, Quasar
Referred to by ATel #: 7205
The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope has observed an increasing gamma-ray activity from a source positionally consistent with the flat spectrum radio quasar CGRaBS J1849+6705 (also known as S4 1849+67 and 1FGL J1849.3+6705, Abdo et al. 2010, ApJS, 188, 405; R.A.= 18:49:16.0723, Dec.=+67:05:41.679, J2000.0; Johnston et al. 1995, AJ, 110, 880) at redshift z = 0.657 (Stickel and Kuhr 1993, A&AS, 100, 395).
Preliminary analysis indicates that CGRaBS J1849+6705 on July 6, 2011 was in a high state, with a daily gamma-ray flux (E > 100 MeV) of (2.5+/-0.3) x10^-6 ph cm^-2 s^-1 (statistical uncertainty only), which represents an increase of a factor of 10 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.
