Fermi-LAT detection of enhanced gamma-ray activity from the flat-spectrum radio source PKS 1453-426
ATel #13641; S. Garrappa (DESY Zeuthen), R. Angioni (SSDC/INFN), C. C. Cheung (NRL) on behalf of the Fermi Large Area Telescope Collaboration
on 16 Apr 2020; 09:22 UT
Credential Certification: Roberto Angioni (r.angioni90@gmail.com)
Subjects: Gamma Ray, >GeV, Request for Observations, AGN
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed enhanced gamma-ray flaring activity from a source positionally consistent with the flat-spectrum radio source PKS 1453-426, also known as 4FGL J1457.3-4246 (The Fermi-LAT collaboration 2020, ApJS, 247, 1), with coordinates R.A. = 224.304083 deg, Decl. = -42.810083 deg (J2000; Healey et al. 2007, ApJ, 171,1), and unknown redshift.
Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on 14 April 2020, with a daily averaged gamma-ray flux (E>100MeV) of (0.9+/-0.2) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). The latter corresponds to a flux increase of a factor of 90 relative to the average flux reported in the fourth Fermi-LAT catalog (4FGL). The corresponding photon index is 2.3+/-0.2, and is consistent with the 4FGL value of 2.5+/-0.1 within the uncertainties.
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. We encourage multifrequency observations of this source. For this source, the Fermi-LAT contact person is Simone Garrappa (simone.garrappa at desy.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.
