Swift/XRT follow-up of the flaring blazar PKS 1424-41
ATel #4717; F. D'Ammando (Univ. Perugia, INFN), M. Orienti (Univ. Bologna, INAF-IRA Bologna) on behalf of the Fermi Large Area Telescope Collaboration
on 9 Jan 2013; 00:01 UT
Credential Certification: Filippo D'Ammando (filippo.dammando@fisica.unipg.it)
Subjects: X-ray, AGN, Black Hole, Blazar, Quasar
Following the optical and gamma-ray flaring activity of the flat spectrum radio quasar PKS 1424-41 (also known as 2FGL J1428.0-4206, Nolan et al. 2012, ApJS, 199, 31) detected by ATOM and Fermi LAT on 2013 January 6 (ATel #4714), a Swift target of opportunity observation was performed on January 7.
Swift/XRT data were taken in Photon Counting mode for a total exposure of about 3.9 ksec. The X-ray spectrum (0.3-10 keV) can be fit by an absorbed power law model with an HI column density consistent with the Galactic value in the direction of the source (n_H = 7.7 x 10^20 cm^-2, Kalberla et al. 2005, A&A, 440, 775) and a photon index of 1.5+/-0.2. The corresponding observed 0.3-10 keV flux is (5.5+/-0.4) x10^-12 erg cm^-2 s^-1. This flux is 50% higher than that observed by Swift/XRT on 2011 May 10, (3.6+/-0.3) x10^-12 erg cm^-2 s^-1, with a photon index of 1.7+/-0.2. Taking into consideration the Swift/XRT observations performed during 2005-2012, PKS 1424-41 reached on 2013 January 7 a high count rate in the 0.3-10 keV energy range, but not comparable to the maximum value observed in 2010 May (http://www.swift.psu.edu/monitoring/source.php?source=PKS1424-418).
Further multiwavelength observations are encouraged. For this source the Fermi LAT contact person is F. Longo (francesco.longo@ts.infn.it).
We would like to thank the Swift Team for making these observations possible, in particular C. Gronwall as Swift Observatory Duty Scientist.