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Fermi LAT detection of a GeV flare from blazar 4C 14.23

ATel #2243; Y. T. Tanaka (ISAS/JAXA), H. Takahashi (Hiroshima University), and S. E. Healey (Stanford/KIPAC)
on 15 Oct 2009; 13:20 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Yasuyuki T. Tanaka (tanaka@astro.isas.jaxa.jp)

Subjects: Gamma Ray, >GeV, Transient

Referred to by ATel #: 2246, 2253

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed an increasing gamma-ray flux from a source positionally consistent with the blazar 4C 14.23 (also known as PKS 0722+145, RA: 07h25m16.81s, Dec: +14d25'13.7", J2000, z=1.038, FSRQ; S. E. Healey et al. 2008, ApJS, 175, 97). Preliminary analysis indicates that the source on Oct. 13 was in a high state with a gamma-ray flux (E>100MeV) of (1.5 +/- 0.4) x 10-6 ph cm-2 s-1, where the quoted error is statistical only. This represents an increase of a factor of ~25 with respect to the source flux level in the past months.

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 strongly encourage multiwavelength observations. For this source the Fermi LAT contact persons are Yasuyuki T. Tanaka (tanaka@astro.isas.jaxa.jp), Hiromitsu Takahashi (hirotaka@hep01.hepl.hiroshima-u.ac.jp) and Stephen E. Healey (sehealey@stanford.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.