Fermi-LAT detection of enhanced gamma-ray activity from the FSRQ TXS 0007+205
ATel #15995; Sara Cutini (INFN Perugia), Denis Bernard (LLR, Ecole Polytechnique & CNRS/IN2P3) and Janeth Valverde (UMBC & NASA/GSFC) on behalf of Fermi-LAT Collaboration
on 19 Apr 2023; 13:27 UT
Credential Certification: Janeth Valverde (valverde@llr.in2p3.fr)
Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Blazar
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed enhanced gamma-ray activity from a source positionally consistent with the flat-spectrum radio quasar TXS 0007+205, also known as 4FGL J0010.6+2043 (The Fermi-LAT collaboration 2022, ApJS, 263, 24, 4FGL-DR3), with coordinates R.A. = 2.61976 deg, Decl. = 20.797163 deg (J2000; Fomalont et al. 2003, AJ, 126, 256), and redshift z=0.59775 (Sexton et al. 2022, ApJS, 260, 33).
Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on April 17, 2023, with a daily averaged gamma-ray flux (E>100MeV) of (0.4+/-0.2) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). This corresponds to a flux increase of a factor greater then 100 times the average flux reported in the fourth Fermi-LAT catalog (4FGL-DR3).
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. The light curve of this source can be obtained through the Fermi-LAT Light Curve Repository (LCR) at https://fermi.gsfc.nasa.gov/ssc/data/access/lat/LightCurveRepository/source.html?source_name=4FGL_J0010.6+2043. We encourage multifrequency observations of this source. For this source, the Fermi-LAT contact person is S. Cutini (sara.cutini.at.pg.infn.it).
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.
