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Fermi LAT Detection of a New Gamma-ray Source Associated with FSRQ CRATES J0944+6135

ATel #10696; R. Angioni (MPIfR- Bonn), S. Buson (NASA GSFC), C. C. Cheung (NRL), E. Bissaldi (Politecnico & INFN Bari) on behalf of the Fermi Large Area Telescope Collaboration
on 2 Sep 2017; 01:09 UT
Credential Certification: Sara Buson (sara.buson@gmail.com)

Subjects: Gamma Ray, Request for Observations, AGN, Blazar, Quasar

The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has observed gamma-ray emission from a source positionally consistent with the flat-spectrum radio source CRATES J0944+6135 (a.k.a. WISE J094420.44+613550.1) with coordinates R.A. = 146.0851667deg, Decl. = 61.5972778 deg (J2000; Healey et al. 2007 ApJS 171, 61) at redshift, z=0.7917 (Hewett & Wild 2010 MNRAS 405, 2302). This source is not in any published LAT catalog and was not detected by AGILE or EGRET.

Preliminary analysis indicates that the source was detected in gamma rays on 2017 August 29 with a daily-averaged flux (E > 100 MeV) of (2.9+/-1.2) x10^-7 ph cm^-2 s^-1 with a single power-law photon index of 2.2+/-0.3 (errors are statistical only). On 2017 August 31 the source brightened to a daily-averaged flux (E > 100 MeV) of (4.6+/-1.1) x10^-7 ph cm^-2 s^-1 with a photon index of 2.3+/-0.4.

Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. In consideration of the ongoing activity of this source, we encourage multiwavelength observations. For this source the Fermi-LAT contact person is R. Angioni (angioni at mpifr-bonn.mpg.de).

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.