Fermi-LAT detection of a bright gamma-ray flare from the blazar PKS B1406-076
ATel #15227; Dario Gasparrini (SSDC/INFN) on behalf of the Fermi-LAT Collaboration
on 17 Feb 2022; 22:27 UT
Credential Certification: Dario Gasparrini (dario.gasparrini@asdc.asi.it)
Subjects: Gamma Ray, Request for Observations, AGN, Blazar
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed gamma-ray flaring activity from a source positionally consistent with the blazar PKS B1406-076, also known as 4FGL J1408.9-0751 (The Fourth Fermi-LAT catalog, 4FGL; Abdollahi, S. et al. 2020, ApJS, 247, 33), with coordinates R.A. = 212.235338 deg, Decl. = -7.874074 deg (J2000; Johnston et al. 1995 AJ, 110, 880), and redshift z=1.494 (Peterson et al. 1979 ApJ, 232, 400).
Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on 16 February 2022, with a daily averaged gamma-ray flux (E>100MeV) of (1.1 +/- 0.2) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). The latter corresponds to a flux increase of about a factor of 25 relative to the average flux reported in the 4FGL. The corresponding photon index is 2.07 +/- 0.16, and is marginally smaller than the 4FGL value of 2.35+/-0.03. A similar flare was reported by Fermi-LAT in July 2020 (ATel #13882).
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. The light curve can be accessed via the Fermi-LAT Light-Curve Repository (LCR) at https://fermi.gsfc.nasa.gov/ssc/data/access/lat/lcr/source.php?source_name=4FGL_J1408.9-0751 and via "LAT Monitored Sources" at https://fermi.gsfc.nasa.gov/ssc/data/access/lat/msl_lc/source/1406-076. We encourage multifrequency observations of this source. For this source, the Fermi-LAT contact person is Sara Buson (sara.buson at 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.
