Fermi LAT detection of an increase in gamma-ray activity of the FSRQ S5 1044+71

ATel #9928; Roopesh Ojha (NASA/GSFC/UMBC) and Bryce Carpenter (NASA/GSFC/CUA) on behalf of the Fermi Large Area Telescope Collaboration
on 3 Jan 2017; 15:43 UT
Credential Certification: Roopesh Ojha (Roopesh.Ojha@gmail.com)

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The Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope, has observed gamma-ray flaring activity from a source positionally consistent with the flat spectrum radio quasar S5 1044+71 (also known as 3FGL J1048.4+7144, Acero et al. 2015, ApJS 218, 23) with radio coordinates R.A: 10h48m27.6199s, Dec: +71d43m35.938s (J2000; Johnston et al. 1995, AJ, 110, 880) and redshift z=1.15 (Polatidis et al. 1995, ApJS, 98, 1).

Preliminary results indicate that S5 1044+71 showed a marked increase in activity on 2016 December 29, with a daily flux (E > 100 MeV) of (1.1+/-0.2) x10^-6 ph cm^-2 s^-1 (errors are statistical only) which is a factor of about 16 greater than the average flux reported in the third Fermi LAT catalog (3FGL). The corresponding photon spectral index of 2.3+/-0.2 was similar to its 3FGL value 2.39+/-0.03. It remains at this elevated flux with a 2017 January 1 daily averaged flux (E > 100 MeV) of (1.1+/-0.2) x10^-6 ph cm^-2 s^-1.

Previous Fermi LAT detection of flaring activity of this source was reported during 2014 January 16-17 (ATel#5784) and 2013 April 1 (ATel#4941). Enhanced activity in the radio band has been reported in the past (ATel#5792, ATel#5869), including the presence of intra-day variability (ATel#6046). Past optical (ATel#5512; includes an observation of rotating optical polarization angle) and NIR (ATel#5739) flaring activity have also been reported.

Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue and its preliminary light curve will be available at the Fermi Science Support Center page (see http://fermi.gsfc.nasa.gov/ssc/data/access/lat/msl_lc/source/S5_1044p71 ). In consideration of the activity of this source we encourage multiwavelength observations. For this source the Fermi-LAT contact person is F. D'Ammando (dammando@ira.inaf.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.