Fermi LAT Detection of a GeV Flare from OP 313 (B2 1308+32)
ATel #6068; Buson Sara (INFN & Univ. of Padova) on behalf of the Fermi LAT collaboration
on 14 Apr 2014; 17:05 UT
Credential Certification: Sara Buson (buson@pd.infn.it)
Subjects: Gamma Ray, >GeV, TeV, VHE, Request for Observations, AGN, Blazar, Transient
The Large Area Telescope (LAT), one of the 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 OP 313 (a.k.a. B2 1308+32, 2FGL J1310.6+3222, Nolan et al. 2012, ApJS, 199, 31). OP 313 has coordinates RA=13h10m28.6s DEC=+32d20m44s, J2000, (Johnston et al. 1995, AJ, 110, 880) and redshift z=0.9980 +/- 0.0005 (Hewett and Wild 2010, MNRAS, 405, 2302).
Preliminary analysis indicates that on 2014 April 14 the source was observed with a daily averaged flux (E>100MeV) of (1.1 +/- 0.2) x 10^-6 ph cm^-2 s^-1 about 13 times its average daily flux from the 2FGL catalog, and a hard spectrum with a photon index of 1.8 +/- 0.2 (statistical uncertainty only). OP 303 is also reported in the 1FHL catalog of LAT sources detected above 10 GeV (1FHL J1310.6+3222, Ackermann et al. 2013, ApJS, 209, 34).
Because Fermi 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 (link: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 Sara Buson (buson@pd.infn.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.
