Fermi-LAT detection of a renewed fast gamma-ray activity from PKS 1824-582
ATel #9471; Sara Cutini (ASDC/INFN) on behalf of the Fermi Large Area Telescope collaboration
on 7 Sep 2016; 21:24 UT
Credential Certification: Dario Gasparrini (dario.gasparrini@asdc.asi.it)
Subjects: Gamma Ray, >GeV, AGN, Blazar, Quasar
Referred to by ATel #: 14013
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed significant gamma-ray emission from a source positionally consistent with the extragalactic radio source PKS 1824-582 with coordinates RA=18h29m12.4023s, Dec=-58d13m55.161s (J2000; Fey et al. 2006, AJ, 132, 1944). This source is classified as an FSRQ at a redshift of 1.531 (Healey et al. 2008, ApJS, 175, 97).
Preliminary analysis indicates that on 2016 September 5, the source was observed with a daily averaged flux (E>100MeV) of (2.5 +/- 0.2) x 10^-6 photons cm^-2 s^-1 and it showed significant intra-day variability, rising from a flux of (0.6 +/- 0.4) x 10^-6 photons cm^-2 s^-1 in the first six-hour interval of the day to (4.1 +/- 0.7) x 10^-6 photons cm^-2 s^-1 in the final six-hour interval (errors are statistical only).
This source showed a similar fast variability in 2014 April (ATel #6067) but it is still not in any published Fermi-LAT catalog and was not detected by EGRET.
Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. We encourage further multifrequency observations of this source. The Fermi LAT contact person is Sara Buson (buson@pd.infn.it).
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.
