Fermi-LAT detection of enhanced gamma-ray activity from the Radio source S5 0532+82
ATel #16117; Adithiya Dinesh (Universidad Complutense de Madrid), on behalf of the Fermi Large Area Telescope Collaboration
on 3 Jul 2023; 20:09 UT
Credential Certification: Janeth Valverde (valverde@llr.in2p3.fr)
Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Blazar
Referred to by ATel #: 16122
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed enhanced gamma-ray activity from a source positionally consistent with the radio source S5 0532+82, also known as 4FGL J0543.2+8238 (The Fermi-LAT collaboration 2020, ApJS, 247, 33), with coordinates (J2000) RA= 85.911862 deg, Dec.: 82.641323 deg (Kovalev et al. 2007, AJ, 133, 1236) and with unknown redshift.
Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on June 30, 2023, with a daily averaged gamma-ray flux (E>100MeV) of 1.6 +/- 0.2 X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). This corresponds to a flux increase of a factor of 220 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 1.8 +/- 0.1, significantly harder than the 4FGL value of 2.5+/-0.1. This is the second time that the Fermi-LAT Collaboration has announced flaring gamma-ray activity from S5 0532+82 (ATel #12902).
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. This source is being added to the "LAT Monitored Sources" and consequently, a preliminary estimation of the daily gamma-ray flux observed by Fermi-LAT will be publicly available at https://fermi.gsfc.nasa.gov/ssc/data/access/lat/msl_lc. We encourage multifrequency observations of this source. For this source, the Fermi-LAT contact person is Stefano Ciprini (stefano.ciprini.asdc@gmail.com).
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.
