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Fermi LAT detection of a GeV flare from the blazar PKS 0250-225

ATel #4574; Michael Dutka (Catholic University of America) and Roopesh Ojha (NASA/GSFC) on behalf of the Fermi Large Area Telescope Collaboration
on 15 Nov 2012; 14:01 UT
Credential Certification: Roopesh Ojha (Roopesh.Ojha@gmail.com)

Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Blazar, Quasar

Referred to by ATel #: 4584, 4601, 4613

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 0250-225 (also known as 2FGL J0252.7-2218, Nolan et al. 2012 ApJS, 199, 31). PKS 0250-225 has the coordinates RA=02h52m47.9536s, DEC=-22d19m25.465s, J2000, (Beasley et al. 2002 ApJS, 141, 13) and redshift z=1.419 (Shaw et al. 2012 ApJ, 748, 49).

Preliminary analysis indicates that on November 13, 2012 the daily averaged flux (E>100MeV) reached (1.0 +/- 0.3) x 10^-6 ph cm^-2 s^-1 (statistical uncertainty only) which is ten times its average flux from the 2FGL catalog. A flare from this source was previously reported on February 19, 2009 (ATel #1933) when it reached a daily flux (E>100MeV) of (0.5 +/- 0.1) x 10^-6 ph cm^-2 s^-1.

Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. Multiwavelength observations during the ongoing activity of this source are strongly encouraged. The Fermi LAT contact person is William McConville (e-mail: wmcconvi@umd.edu).

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.