Support ATel At Patreon

[ Previous | Next | ADS ]

Fermi-LAT detection of a bright gamma-ray flare from the blazar PKS B1406-076

ATel #13882; S. Buson (Univ. of Wuerzburg) on behalf of the Fermi-LAT collaboration
on 20 Jul 2020; 20:24 UT
Credential Certification: Sara Buson (sara.buson@gmail.com)

Subjects: Gamma Ray, Request for Observations, AGN, Blazar

Referred to by ATel #: 13887, 13906, 15227

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; The Fermi-LAT collaboration 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 18 July 2020, with a daily averaged gamma-ray flux (E>100MeV) of (1.2 +/- 0.2) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). The latter corresponds to a flux increase of a factor of 40 relative to the average flux reported in the 4FGL. The corresponding photon index is 2.2 +/- 0.1, and is marginally smaller than the 4FGL value of 2.35+/-0.03. A preliminary analysis of the latest LAT data of July 19 2020 finds that the source is detected with comparable brightness and spectral shape.

Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. This source is included in the "LAT Monitored Sources" and consequently, a preliminary estimation of the daily gamma-ray flux observed by Fermi-LAT will be publicly available (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.