Fermi LAT Detection of a Bright GeV Flare from the FSRQ PKS 1622-253
ATel #5452; Bryce Carpenter (Catholic U.), Roopesh Ojha (NASA/GSFC/ORAU), on behalf of the Fermi Large Area Telescope Collaboration
on 8 Oct 2013; 13:09 UT
Credential Certification: Roopesh Ojha (Roopesh.Ojha@gmail.com)
Subjects: Gamma Ray, >GeV, AGN, Blazar, Quasar
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 1622-253 (RA=16h25m46.8916s, Dec=-25d27m38.326s, J2000;
Beasley et al. 2002, ApJS, 141, 13) at z= 0.786 (di Serego Alighieri
et al. 1994, MNRAS, 269, 998).
Preliminary analysis indicates that on October 6, 2013, the daily
averaged flux (E>100MeV) was (3.0 +/- 0.3) x 10^-6 photons cm^-2 s^-1
(errors are statistical only), which is the highest ever recorded for
this source and is 22 times its average flux in the 2FGL catalog
(2FGL J1625.7-2526; Nolan et al. 2012, ApJS, 199, 31). This source was previously observed in a gamma-ray active state in June 2011 (ATel #3424) and October 2009 (ATel #2231).
Because Fermi operates in an all-sky scanning mode, regular gamma-ray
monitoring of this source will continue. This source is one of the "LAT Monitored Sources" and consequently a preliminary estimation of the daily gamma-ray flux observed by Fermi LAT is publicly available at
(http://fermi.gsfc.nasa.gov/FTP/glast/data/lat/catalogs/asp/current/lightcurves/PKS1622-253_86400.png). We encourage further multifrequency observations of this source. For this source the Fermi LAT contact person is Luis C. Reyes (lreyes04@calpoly.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.
