Swift follow-up of the flaring NLSy1 PKS 1502+036
ATel #8450; Filippo D'Ammando (DIFA - University of Bologna, INAF-IRA) on behalf of the Fermi Large Area Telescope Collaboration
on 22 Dec 2015; 22:55 UT
Credential Certification: Filippo D'Ammando (filippo.dammando@fisica.unipg.it)
Subjects: Optical, Ultra-Violet, X-ray, AGN, Black Hole, Blazar
Following the gamma-ray flare of the radio-loud narrow-line Seyfert 1 PKS 1502+036 detected by Fermi LAT on 2015 December 20 (ATel #8447), a Swift target of opportunity observation was performed on December 22.
Swift/XRT data were taken in Photon Counting mode for a net exposure of about 3.0 ksec. The X-ray spectrum (0.3-10 keV) observed on 2015 December 22 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 = 3.9x10^20 cm^-2, Kalberla et al. 2005, A&A, 440, 775) and a photon index of 1.5+/-0.4. The corresponding unabsorbed 0.3-10 keV flux is (1.9+/-0.6)x10^-12 erg cm^-2 s^-1. This flux is a factor of five higher than that observed by Swift/XRT during 2012 April-August, (3.5-4.0)x10^-13 erg cm^-2 s^-1, with a photon index varying between 1.7+/-0.4 and 2.2+/-0.3 (D'Ammando et al. 2013, MNRAS, 433, 952).
Simultaneous Swift/UVOT observations on 2015 December 22 found PKS 1502+036 about 0.4 mag brighter in V-band (V = 18.32+/-0.24), 0.6 mag in U-band (U = 18.10+/-0.18), and 0.7 mag in M2-band (M2 = 17.89+/-0.11) compared to the UVOT observations performed on 2012 May 25 (V = 18.72+/-0.31, U = 18.74+/-0.06, M2 = 18.60+/-0.17; D'Ammando et al. 2013, MNRAS, 433, 952).
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 F. D'Ammando (dammando@ira.inaf.it).
We would like to thank the Swift Team for making this observation possible, in particular M. H. Siegel as the Swift Observatory Duty Scientist.
