Swift follow-up of the flaring NLSy1 PKS 2004-447
ATel #13233; F. D'Ammando (INAF-IRA Bologna), A. Gokus (University of Wuerzburg, Remeis Observatory Bamberg & ECAP) , M. Kadler (University of Wuerzburg), and R. Ojha (NASA Goddard Space Flight Center) on behalf of the Fermi Large Area Telescope Collaboration
on 28 Oct 2019; 14:15 UT
Credential Certification: Filippo D'Ammando (dammando@ira.inaf.it)
Subjects: Optical, Ultra-Violet, X-ray, Gamma Ray, Request for Observations, AGN, Black Hole, Blazar, Quasar
Following the flaring activity of the narrow-line Seyfert 1 galaxy PKS 2004-447 at z = 0.24 (Drinkwater et al. 1997, MNRAS, 284, 85) observed in gamma-rays by Fermi-LAT on October 25 (ATel #13229), a Swift target of opportunity observation was performed on October 27.
Swift-XRT data were taken in Photon Counting mode for a net exposure of about 2.9 ksec. The X-ray spectrum (0.3-10 keV) observed in 2019 October 27 can be fit by an absorbed power law model with a HI column density consistent with the Galactic value in the direction of the source (n_H = 3.2 x 10^20 cm^-2, Kalberla et al. 2005, A&A, 440, 775) and a photon index of 1.56 +/- 0.24. The corresponding unabsorbed 0.3-10 keV flux is (18.5+/-3.6) x10^-13 erg cm^-2 s^-1. This flux is higher than all values observed during the monitoring of the source in 2011-2014 (3.9-15.5 x10^-13 erg cm^-2 s^-1; Orienti et al. 2015, MNRAS, 453, 4037, Kreikenbohm et al. 2016, A&A, 585, A91).
Simultaneous Swift-UVOT observations were performed on 2019 October 27. The measured magnitudes are V = 17.03 +/-0.09, B = 17.59 +/- 0.10, U = 17.28 +/- 0.11, W1 = 17.65 +/- 0.14, M2 = 17.64 +/- 0.29, W2 = 18.55 +/- 0.14. The source is more than 1 magnitude brighter in optical and UV with respect to the values observed during 2011-2014 (Orienti et al. 2015, MNRAS, 453, 4037). This confirms the high activity state of the source in optical, UV and X-rays.
In consideration of the ongoing activity of this source, confirmed also by the Swift observations, we encourage further multiwavelength observations. For this source the Fermi LAT contact person is Andrea Gokus (andrea.gokus@astro.uni-wuerzburg.de) .
We would like to thank the Swift Team for making these observations possible, in particular K. L. Page as the Swift Observatory Duty Scientist.
