Fermi LAT detection of gamma-ray flaring activity from Broad Line Radio Galaxy 3C 120
ATel #6529; Y. T. Tanaka (Hiroshima University), S. Cutini (ASDC & INAF), S. Ciprini (ASDC & INAF), C. C.Cheung (NRL), R. Buehler (Desy-Zeuthen), D. Kocevski (NASA/GSFC) on behalf of the Fermi Large Area Telescope Collaboration
on 3 Oct 2014; 12:06 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Yasuyuki T. Tanaka (tanaka@astro.isas.jaxa.jp)
Subjects: Gamma Ray, >GeV, AGN, Transient
The Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope, detected a transient gamma-ray source positionally consistent with Broad Line Radio Galaxy (BLRG) 3C 120. Preliminary analysis of the Fermi-LAT data indicates that on September 24 , 2014, the source was detected with a flux (E >100 MeV) of (1.0+/-0.3) x 10^-6 ph cm^-2 s^-1 (errors are statistical only).
Gamma-ray flaring activity of 3C 120 was also confirmed by a new method implemented within the Fermi-LAT Collaboration known as `Fermi All-sky Variability Analysis' that searches the sky for high-energy transients on weekly time scales (Ackermann et al. 2013, ApJ, 771, 57). During the week between September 22 and 29, 2014, this method also indicates increased gamma-ray activity from a source positionally coincident with BLRG 3C 120. Preliminary analysis indicates that the source brightened in gamma rays to a weekly-averaged flux (E > 100 MeV) of (4.5+/-0.9) x10^-7 ph cm^-2 s^-1 (errors are statistical only).
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 strongly encourage multiwavelength observations. For this source the Fermi LAT contact person is Yasuyuki Tanaka (ytanaka@hep01.hepl.hiroshima-u.ac.jp).
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.
