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Fermi LAT detection of increasing gamma-ray activity of blazar PKS 2052-474

ATel #2160; C. S. Chang (MPIfR), on behalf of the Fermi Large Area Telescope Collaboration
on 15 Aug 2009; 00:30 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Teddy Cheung (ccheung@milkyway.gsfc.nasa.gov)

Subjects: Gamma Ray, >GeV, Transient

Referred to by ATel #: 2162

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 PKS 2052-474 (RA=20:56:16.3, DEC=-47:14:47.6, J2000; Ma, C. et al., 1998, AJ, 116,516). Recent optical flaring of this source is reported in ATEL #2158 (Hauser et al.).

Preliminary analysis indicates that this source has recently brightened. On 9 August 2009 it reached a relatively high state with a gamma-ray flux (E>100MeV) of (8.7 ± 1.6) x 10-7 ph cm-2 s-1 (statistical errors only) for that day. This is a factor of 4 higher than the average level observed in the previous week of all-sky monitoring (29 July - 4 August 2009). The gamma-ray outburst may now be fading, thus we strongly encourage prompt followup observations.

Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. For this source the Fermi LAT contact person is C. S. Chang (cschang@mpifr.de).

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.