Fermi-LAT detection of enhanced gamma-ray activity from the high-redshift FSRQ PKS 0601-70
ATel #13506; I. Mereu (INFN Perugia), R. Angioni (SSDC/INFN), S. Cutini (INFN Perugia), and C. C. Cheung (NRL), on behalf of the Fermi Large Area Telescope Collaboration
on 19 Feb 2020; 23:02 UT
Credential Certification: Roberto Angioni (r.angioni90@gmail.com)
Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Quasar
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 PKS 0601-70, also known as 4FGL J0601.1-7035 (The Fermi-LAT collaboration 2019, arXiv:1902.10045), with coordinates R.A. = 90.297167 deg, Decl. = -70.602389 deg (J2000; Healey et al. 2007, ApJS, 171, 61), and redshift z=2.409 (Shaw et al. 2012, ApJ, 748, 49).
Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on February 17, 2020, with a daily averaged gamma-ray flux (E>100MeV) of (6.9+/-1.8) X 10^-7 photons cm^-2 s^-1 (statistical uncertainty only). It corresponds to a flux increase of a factor of 17 relative to the average flux reported in the fourth Fermi-LAT catalog (4FGL). This is the highest LAT daily flux ever observed for this source. The corresponding photon index is 2.4+/-0.2, and is consistent with the 4FGL value of 2.40+/-0.03.
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. The Fermi-LAT contact person for this source is I. Mereu (isabella.mereu@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.
