Fermi LAT detection of renewed activity from the blazar PKS 1502+106

ATel #7592; Stefano Ciprini (ASDC Rome & INFN Perugia, Italy), on behalf of the Fermi Large Area Telescope Collaboration.
on 5 Jun 2015; 11:17 UT
Credential Certification: Stefano Ciprini (stefano.ciprini@asdc.asi.it)

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The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source positionally consistent with the flat spectrum radio quasar PKS 1502+106 (also known as OR 103, S3 1502+10 and 3FGL J1504.4+1029, Acero et al. 2015, arXiv:1501.02003), with radio coordinates, (J2000.0), R.A.: 226.10408 deg, Dec: 10.49422 deg (Johnston et al. 1995, AJ, 110, 880). This blazar has a redshift of z=1.8383 (Hewett & Wild 2010, MNRAS, 405, 2302).

Preliminary analysis indicates that the source was in a high state in the last week with a daily gamma-ray flux (E>100MeV) around or above 10^-6 photons cm^-2 s^-1. In particular on May 28 and June 3, 2015 the gamma-ray flux (E>100MeV) was respectively (1.3+/-0.3) X 10^-6 and (0.9+/-0.3) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). The spectral photon index (E>100MeV) was respectively (2.6+/-0.3) and (2.4+/-0.3). This is the third time that Fermi is announcing gamma-ray flaring activity from this blazar (after August 2008, ATel#1650, and January 2009, ATel#1905).

This source is one of the "LAT Monitored Sources" and consequently a preliminary estimation of the daily gamma-ray flux observed by Fermi LAT is publicly available (http://fermi.gsfc.nasa.gov/ssc/data/access/lat/msl_lc/source/PKS_1502p106).

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 S. Ciprini (stefano.ciprini@asdc.asi.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.