Swift follow-up observations of the blazar PKS 0420-014
ATel #14889; F. D'Ammando (INAF-IRA Bologna)
on 2 Sep 2021; 14:59 UT
Credential Certification: Filippo D'Ammando (dammando@ira.inaf.it)
Subjects: X-ray, AGN, Black Hole, Blazar, Quasar
Following the mm/sub-mm flaring activity from the flat spectrum radio quasar PKS 0420-014 observed by ALMA on 2021 August (see ATel #14847), Swift target of opportunity observations were performed on 2021 August 17, 25, and 31.
Taking into consideration the Swift observations performed during 2007-2021, the source reached on 2021 August 31 the highest count rate observed in the 0.3-10 keV energy range (see Swift-XRT Monitoring of Fermi-LAT Sources of Interest). Swift/XRT data were taken in Photon Counting mode for a net exposure of about 2.2 ksec, 1.8 ksec, and 1.4 ksec on 2021 August 17, 25, and 31, respectively. The X-ray spectrum (0.3-10 keV) of PKS 0420-014 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 = 8.6 x 10^20 cm^-2; Ben Bekhti et al. 2016, A&A, 594, A116) and a photon index of 1.60 +/- 0.11, 1.56 +/- 0.13, and 1.49 +/- 0.15, respectively. The corresponding observed 0.3-10 keV fluxes are (10.0 +/- 0.6)e-12, (10.8 +/- 0.7)e-12, and (12.9 +/- 1.3)e-12 erg cm^-2 s^-1, respectively. By comparison, the flux estimated in the previous XRT observations of PKS 0420-014 ranges between (1.9-6.8)e-12 erg cm^-2 s^-1, indicating a clear increase of X-ray activity in 2021 August, in agreement with the observed mm/sub-mm flaring activity.
In consideration of the ongoing activity of this source, confirmed also by the Swift-XRT observations, we encourage further multi-wavelength observations.
We would like to thank the Swift Team, Observatory Duty Scientists, and PI for making these observations possible.
