Fermi LAT detection of renewed gamma-ray flaring activity from the distant blazar PKS 0226-559
ATel #12432; S. Buson (Univ. of Wuerzburg, UMBC) and R. Angioni (MPIfR- Bonn) on behalf of the Fermi Large Area Telescope Collaboration
on 26 Jan 2019; 19:12 UT
Credential Certification: Sara Buson (sara.buson@gmail.com)
Subjects: >GeV, Request for Observations, AGN, Blazar, Quasar
The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray emission from a source positionally consistent with the flat spectrum radio quasar PKS 0226-559 (also known as PMN J0228-5546, CGRaBS J0228-5546 and 3FGL J0228.3-5545) with radio coordinates (J2000) R.A.: 37.09004 deg, Dec.: -55.76764 deg (Fey et al. 2015, AJ, 150, 58). This blazar has a high redshift, z=2.471 (Mahony et al. 2011, MNRAS, 417, 2651).
PKS 0226-559 has brightened in GeV gamma rays since the past week. Preliminary analysis indicates that on January 25, 2019, PKS 0226-559 was in a flaring state with a daily averaged gamma-ray flux (E>100 MeV) of (1.0+/-0.2) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only), about 40 times greater than its four-year average flux reported in the third Fermi-LAT source catalog (3FGL, Acero et al. 2015, ApJS, 218, 23). The corresponding photon spectral index (E>100 MeV) of 2.0+/-0.1 (statistical uncertainty only) is smaller than the 3FGL catalog value of 2.43+/-0.06. Previous enhanced gamma-ray activity from this source has been reported about a year ago, in February 2018 (ATel #11283).
Since Fermi normally 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 at ssdc.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.
