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Fermi LAT Detection of a Bright GeV Flare from the FSRQ PKS 1441+25

ATel #6878; Roopesh Ojha (NASA/GSFC/UMBC), on behalf of the Fermi Large Area Telescope Collaboration
on 5 Jan 2015; 23:57 UT
Credential Certification: Roopesh Ojha (Roopesh.Ojha@gmail.com)

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

Referred to by ATel #: 6895, 6923, 7402, 7459

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source positionally consistent with the flat spectrum radio quasar PKS 1441+25 (RA=14h43m56.8922s, Dec=+25d01m44.490s, J2000; Fomalont et al. 2003, AJ, 126, 2562) at z= 0.939 (Shaw et al. 2012, ApJ, 748, 49).

Preliminary analysis indicates that on Jan 3, 2015, the daily averaged flux (E>100MeV) was (0.7 +/- 0.2) x 10^-6 photons cm^-2 s^-1 (errors are statistical only), which is the highest ever recorded for this source and is about 70 times its average flux in the 2FGL catalog (2FGL J1444.1+2500; Nolan et al. 2012, ApJS, 199, 31).

Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. We encourage further multifrequency observations of this source. For this source the Fermi LAT contact person is Roopesh Ojha (Roopesh.Ojha@gmail.com).

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.