Fermi LAT detection of a GeV flare from PKS 0517-726
ATel #12333; B. Rani (NASA/GSFC), M. Kreter (North-West University, Potchefstroom), C. C. Cheung (NRL), on behalf of the Fermi Large Area Telescope Collaboration
on 27 Dec 2018; 16:09 UT
Credential Certification: Teddy Cheung (Teddy.Cheung@nrl.navy.mil)
Subjects: Gamma Ray, >GeV, AGN, Blazar, Transient
The Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope, has observed a gamma-ray flare from a source positionally consistent with the flat-spectrum radio source, PKS 0517-726 (RA = 79.1571608 deg, Decl. = -72.6187408 deg, J2000; Johnston et al. 1995 AJ 110, 880), with no known redshift.
Preliminary analysis indicates that on December 25, 2018 the source was in a high state with a gamma-ray daily averaged flux (E>100MeV) of (0.4 +/- 0.1) x10^-6 ph cm^-2 s^-1 (uncertainty is statistical only), and a single power-law photon index of 2.5 +/- 0.3. It was also detected on December 14, 2018 with the same flux of (0.4 +/- 0.1) x 10^-6 ph cm^-2 s^-1, but with a harder spectrum (photon index = 1.8 +/- 0.2). The source was initially reported as a low-significance LAT source in the LMC field (Abdo et al. 2010 A&A 512, 7).
Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. In consideration of the activity of this source we strongly encourage multiwavelength observations. The Fermi LAT contact person for this source is B. Rani (bindu.rani at nasa.gov).
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.
