Highest gamma-ray flux level detected from very high redshift blazar B3 1343+451
ATel #3793; Roopesh Ojha (NASA/GSFC), Michael Dutka (Catholic U.) & Eleonora Torresi (INAF-IASF Bologna) on behalf of the Fermi Large Area Telescope Collaboration
on 1 Dec 2011; 16:10 UT
Credential Certification: Roopesh Ojha (Roopesh.Ojha@gmail.com)
Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Blazar, Quasar
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed gamma-ray flux increasing to a record level from a source positionally consistent with the flat spectrum radio quasar B3 1343+451 also known as 2FGL J1345.4+4453 (RA: 13h45m33.172s, Dec: +44d52m59.57s, J2000, Kovalev, Y. Y. et al., 2007, AJ 133, 1236). Its redshift of 2.534 (Shaw, M. S. et al., ApJ, Submitted) makes this object one of the ten most distant quasars detected by Fermi/LAT (Ackermann et al. 2011, ApJ, In Press, arXiv:1108.1420).
This source has been intermittently detected by Fermi/LAT from October 9th with daily-averaged flux levels in the range (0.2-0.9) x 10^-6 photons cm^-2 s^-1 in the 100 MeV to 300 GeV energy range. Since November 24th it has steadily risen from a daily-averaged value 0.6 x 10^-6 photons cm^-2 s^-1 to its highest recorded value of (1.2+/-0.2) x 10^-6 photons cm^-2 s^-1 on November 29th. This is about 16 times greater than the average flux reported in the second Fermi LAT catalog (2FGL). The previous highest daily-averaged flux was measured on the 25th of September 2009, at (1.02+/-0.28) x 10-6 ph s-1 cm-1 (ATel#2217).
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 at http://fermi.gsfc.nasa.gov/FTP/glast/data/lat/catalogs/asp/current/lightcurves/B31343+451_86400.png
Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. Multiwavelength observations during the ongoing activity of this source are strongly encouraged. The Fermi LAT contact person is: Rolf Buehler (buehler@slac.stanford.edu).
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.
