Fermi-LAT detection of renewed gamma-ray activity from the FSRQ S3 0458-02
ATel #16110; Adithiya Dinesh, (Universidad Complutense de Madrid), on behalf of the Fermi Large Area Telescope Collaboration
on 2 Jul 2023; 14:28 UT
Credential Certification: Denis Bernard (Denis.bernard@in2p3.fr)
Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Blazar
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed renewed gamma-ray activity from a source positionally consistent with the flat-spectrum radio quasar S3 0458-02, also known as 4FGL J0501.2-0158 (The Fermi-LAT collaboration 2020, ApJS, 247, 33), with coordinates R.A. = 75.303 deg, Decl. = -1.987 deg (J2000; Johnston et al. 1995, AJ, 110, 880), and redshift z=2.286 (Strittmatter et al. 1974, ApJ, 190, 509). (Previous ATel )
Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on June 26, 2023 , with a daily averaged gamma-ray flux (E>100MeV) of 1.7 ± 0.4 X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). This corresponds to a flux increase of a factor of 7 relative to the average flux reported in the fourth Fermi-LAT catalog (4FGL). This is the highest LAT daily flux ever observed for this source. The corresponding photon index is 2.6+/-0.3, and is consistent with the 4FGL value of 2.373+/-0.014 within the uncertainties.
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. In consideration of the ongoing activity of this source we will keep searching in the next days for any delayed gamma-ray activity. For this source, the Fermi-LAT contact person is M. Orienti (orienti@ira.inaf.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.
