Fermi-LAT detection of enhanced gamma-ray activity from the FSRQ GB6 J0043+3426
ATel #13617; S. Buson (Univ. of Wuerzburg), R. Angioni (SSDC/INFN), on behalf of the Fermi Large Area Telescope Collaboration
on 5 Apr 2020; 11:12 UT
Credential Certification: Sara Buson (sara.buson@gmail.com)
Subjects: Gamma Ray, >GeV, Request for Observations, 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 flat-spectrum radio quasar GB6 J0043+3426, also known as 4FGL J0043.8+3425 (4FGL; The Fermi-LAT collaboration 2020, ApJS, 247, 33), with coordinates R.A. = 10.953525 deg, Decl. = 34.440589 deg (J2000; Jackson et al 2007 MNRAS, 376, 371), and redshift z= 0.966 (Shaw et al. 2012, ApJ, 748, 49).
Preliminary analysis indicates that this object is in an elevated gamma-ray emission state. Integrating the LAT data between March 26 - April 2, 2020, the weekly averaged gamma-ray flux (E>100MeV) is (1.7+/-0.3) X 10^-7 photons cm^-2 s^-1 (statistical uncertainty only). It corresponds to a flux increase of a factor of about 10 relative to the average flux reported in the fourth Fermi-LAT catalog. This is among the highest weekly fluxes observed by the LAT so far for this source. The corresponding weekly photon index is 1.6+/-0.1, significantly smaller than the 4FGL value of 1.94+/-0.02. Preliminary analysis reveals that during the past two weeks several high-energy (>10 GeV) photons are positionally consistent with this source and have high probability of being associated with it. Among them, the highest-energy one has an energy of 56 GeV (detected at 2020-03-31 21:25:58).
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. The Fermi-LAT contact person for this source is S. 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.
