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Fermi LAT detection of increase gamma-ray emission from OJ 248

ATel #4421; M. Orienti (Univ. Bologna, INAF-IRA Bologna), F. D'Ammando (Univ. Perugia, INFN) on behalf of the Fermi Large Area Telescope Collaboration
on 25 Sep 2012; 07:32 UT
Credential Certification: Monica Orienti (orienti@ira.inaf.it)

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

Referred to by ATel #: 4440

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 OJ 248 (also known as 2FGL J0830.5+2407, Nolan et al. 2012, ApJS, 199, 31) with radio coordinates R.A.: 127.7170254 deg, Dec: 24.1832836 deg (J2000, Johnston et al. 1995, AJ, 110, 880) at redshift z=0.94 (Hewitt & Burbidge 1993, ApJS, 87, 451).

Preliminary analysis indicates that the source brightened in gamma rays with a daily flux (E > 100 MeV) of (1.1+/-0.3) x10^-6 ph cm^-2 s^-1 (errors are statistical only) on 23 September 2012, about a factor of 20 greater than the average flux reported in the second Fermi LAT catalog (2FGL, Nolan et al. 2012, ApJS, 199, 31).

Because Fermi is currently operating in Target of Opportunity pointed observations of S3 0218+35, further LAT observations of OJ 248 will be extremely limited until routine sky survey observations resume at 12:00 UTC on 30 September 2012. In consideration of the ongoing activity of this source we encourage multiwavelength observations. For this source the Fermi LAT contact person is M. Orienti (orienti@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.