Fermi-LAT detection of renewed gamma-ray activity from the FSRQ PKS 0035-252
ATel #11854; R. Angioni (MPIfR-Bonn), Janeth Valverde (LLR/Ecole Polytechnique) and Roopesh Ojha (NASA/GSFC/UMBC) on behalf of the Fermi-LAT Collaboration
on 14 Jul 2018; 22:00 UT
Credential Certification: Sara Buson (sara.buson@gmail.com)
Subjects: Gamma Ray, >GeV, Request for Observations, AGN
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed renewed gamma-ray flaring activity from a source positionally consistent with the flat-spectrum radio quasar PKS 0035-282, also known as 3FGL J0038.0-2501 (Acero et al. 2015, ApJS, 218, 23), with coordinates R.A. = 9.5613975 deg, Decl. = -24.9839542 deg (J2000; Beasley et al. 2002 ApJS, 141, 13), and redshift z=0.49806 (Jones et al. 2009, MNRAS, 399, 683).
Preliminary analysis indicates that this source went into a high-flux state starting on 30 June 2018, and brightened over the following weeks, reaching a daily averaged gamma-ray flux (E>100MeV) of (1.6+/-0.2) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only) on 13 July 2018. The latter corresponds to a flux increase of a factor of more than 120 relative to the average flux reported in the third Fermi-LAT catalog (3FGL). This is the highest LAT daily flux ever observed for this source, exceeding that observed during a previous flaring episode in November 2017, reported in ATel #10951. The corresponding photon index is 2.2+/-0.1, and is consistent with the 3FGL value of 2.4+/-0.1 within the uncertainties.
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. This source is being added to the "LAT Monitored Sources" and consequently, a preliminary estimation of the daily gamma-ray flux observed by Fermi-LAT will be publicly available (http://fermi.gsfc.nasa.gov/ssc/data/access/lat/msl_lc/). We encourage further multifrequency observations of this source. For this source, the Fermi-LAT contact person is Janeth Valverde (valverde@llr.in2p3.fr).
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.
