PKS 1329-049 revived: new gamma-ray activity observed by Fermi LAT
ATel #2837; K. V. Sokolovsky (MPIfR/ASC Lebedev) and F. K. Schinzel (MPIfR); on behalf of the Fermi Large Area Telescope Collaboration
on 9 Sep 2010; 09:28 UT
Distributed as an Instant Email Notice Request For Observations
Credential Certification: Frank Schinzel (email@example.com)
Subjects: Gamma Ray, >GeV, Request for Observations, Blazar, Quasar, Transient
The Large Area Telescope (LAT), one of the two instruments aboard the Fermi
Gamma-ray Space Telescope, has observed a sharply increasing gamma-ray flux from a
source positionally consistent with the high-redshift blazar PKS 1329-049
(1FGL J1331.9-0506, Abdo et al. 2010, ApJS, 188, 405; z = 2.15, Thompson et al. 1990, PASP, 102, 1235).
Preliminary analysis indicates that the source on September 06, 2010, was in
a high state with a gamma-ray flux (E>100MeV) of (3.0 +/-0.5) x10^-6 photons
cm^-2 s^-1 (all errors are statistical only), making it the brightest source in
the extragalactic gamma-ray sky on that day. On September 07, the source was
still bright with a flux of (2.3 +/-0.7) x10^-6 photons cm^-2 s^-1.
Previously, the source was detected by Fermi on the 1-day timescale on
September 22, 2009, and July 07, 2010, at a flux level of about 1.0 x10^-6
photons cm^-2 s^-1 (ATel #2728).
Because Fermi operates in an all-sky scanning mode, regular gamma-ray
monitoring of PKS 1329-049 will continue. The source is currently only 37
degrees away from the Sun which makes multiwavelength observations
challenging, however we strongly encourage follow-up in other bands if
possible. The Fermi LAT contact person for this source is D. Donato
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.