Fermi-LAT detection of high gamma-ray activity from the z=3.6 quasar NVSS J163547+362930
ATel #11847; Vaidehi S. Paliya (Clemson Univ.), C. C. Teddy Cheung (NRL), Daniel Kocevski (NASA/MSFC), Roberto Angioni (MPIfR-Bonn), on behalf of the Fermi-LAT collaboration
on 13 Jul 2018; 16:01 UT
Credential Certification: Vaidehi S. Paliya (vaidehiratna@gmail.com)
Subjects: Gamma Ray, >GeV, AGN, Blazar, Quasar
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray activity from a source positionally consistent with the flat-spectrum radio quasar NVSS J163547+362930 with coordinates R.A. = 248.94682 deg, Decl. = +36.49166 deg (J2000; Petrov & Taylor 2011, AJ, 142, 89), and redshift z=3.6 (Paris et al., 2014, A&A, 563, A54).
Preliminary analysis indicates that this source went into a high-flux state starting on 2018 July 7, reaching a peak daily averaged gamma-ray flux (E>100MeV) of (6.4+/-1.5) X 10^-7 photons cm^-2 s^-1 (statistical uncertainty only) on July 8. This is the highest LAT daily flux ever observed for this source. This quasar was recently reported as a new gamma-ray emitter by Ackermann et al. (2017, ApJL, 837, 5). The corresponding photon index is 2.6+/-0.2, indicating a harder spectrum than that reported in Ackermann et al. (photon index = 3.2+/-0.1).
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. We encourage further multifrequency observations of this source. For this source the Fermi-LAT contact persons are Vaidehi S. Paliya (vpaliya@g.clemson.edu) and C. C. Teddy Cheung (teddy.cheung@nrl.navy.mil).
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.
