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Fermi LAT detection of recent activity in the new gamma-ray blazar PKS 0805-07

ATEL # 2048; S. Ciprini (Univ./INFN Perugia) on behalf of the Fermi Large Area Telescope Collaboration
on 16 May 2009; 18:36 UT
Distributed as an Instant Email Notice (Request for Observations)
Password Certification: Stefano Ciprini (

Subjects: Radio, Millimeter, Gamma Ray, >GeV, AGN, Quasars

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope (formerly GLAST, launched June 11, 2008), discovered and recorded since mid April 2009 increasing gamma-ray activity from a source positionally consistent with the flat spectrum radio quasar PKS 0805-07 (RA: 08h 08m 15.536s, Dec -07d 51m 09.88s, J2000.0, redshift 1.837), which exhibits one of the fastest superluminal motions known to date.

Preliminary analysis indicates that on May 14, 2009, this source appeared in a high state with a gamma-ray flux (E>100MeV) of 0.83+/-0.30 x 10^-6 photons cm^-2 s^-1 (statistical only), one order of magnitude higher than the average flux estimated over the first six months of the Fermi survey. The first flaring activity was observed already on April 30, when PKS 0805-07 shown a flux exceeding the level observed on May 14.

Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. In consideration of the ongoing gamma-ray activity, the rather high redshift and the very fast superluminal motions of this source, we strongly encourage multiwavelength observations. For this source the Fermi LAT contact person is S. Ciprini (

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.

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