Fermi-LAT detection of renewed gamma-ray activity from the FSRQ NRAO 190 (PKS 0440-00)
ATel #16395; Denis Bernard (LLR, Ecole Polytechnique & CNRS / IN2P3), on behalf of the Fermi Large Area Telescope Collaboration
on 6 Jan 2024; 17:06 UT
Credential Certification: Denis Bernard (Denis.bernard@in2p3.fr)
Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Blazar, Quasar
Referred to by ATel #: 16563
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed renewed gamma-ray activity from a source positionally consistent with the flat spectrum radio quasar NRAO 190 (also known as PKS 0440-00 and 4FGL J0442.6-0017, The Fermi-LAT collaboration 2020, ApJS, 247, 33), with coordinates R.A. = 70.661086 deg, Decl. = -0.295394 deg (J2000; Johnston et al., 1995, AJ, 110, 880), and redshift z=0.844 (Hewitt & Burbidge 1987, ApJS, 63, 1).
Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on January 5, 2024, with a daily averaged gamma-ray flux (E>100MeV) of (1.3 +/- 0.4) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). This corresponds to a flux increase of a factor of 15 relative to the average flux reported in the fourth Fermi-LAT catalog (4FGL). The corresponding photon index is 2.76 +/- 0.27, and is significantly larger than the 4FGL value of 2.44 +/- 0.02. The source was detected in a similar high gamma-ray state in May 2009 (ATel #2049) and June 2013 (ATel #5156).
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. Monitoring of this source is publicly available on the "LAT Monitored Sources" page at https://fermi.gsfc.nasa.gov/ssc/data/access/lat/msl_lc/source/NRAO_190 and on the "Light Curve Repository" at https://fermi.gsfc.nasa.gov/ssc/data/access/lat/LightCurveRepository/source.html?source_name=4FGL_J0442.6-0017 . We encourage multifrequency observations of this source. For this source, the Fermi-LAT contact persons are S. Ciprini (stefano.ciprini@ssdc.asi.it) and F. Longo (francesco.longo@ts.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.
