Fermi-LAT detection of renewed gamma-ray flaring activity from the blazar PMN J2052-5533

ATel #14120; A. Gokus (Remeis Observatory/ECAP & University of Wuerzburg) on behalf of the Fermi Large Area Telescope Collaboration
on 26 Oct 2020; 19:51 UT
Credential Certification: Roberto Angioni (r.angioni90@gmail.com)

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The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed renewed gamma-ray flaring activity from a source positionally consistent with the blazar PMN J2052-5533, also known as 4FGL J2052.2-5533 (The Fermi-LAT collaboration 2020, ApJS, 247, 33), with coordinates R.A. = 313.0570 deg, Decl. = -55.5528 deg (J2000; Healey et al. 2007, ApJS, 171, 61), and unknown redshift.

Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on October 25, 2020 , with a daily averaged gamma-ray flux (E>100MeV) of (7.8+/- 2.1) X 10^-7 photons cm^-2 s^-1 (statistical uncertainty only). The latter corresponds to a flux increase of a factor of 35 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 1.89 +/- 0.19, and is significantly smaller than the 4FGL value of 2.31 +/- 0.04. The source has been reported in an enhanced state once, in September 2015, when the flux reached a daily-averaged value of 0.3 +/- 0.1 X 10^-6 photons cm^-2 s^-1(ATel #8096).

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 Andrea Gokus (andrea.gokus@fau.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.