Swift-XRT follow-up confirms the high activity state of the FSRQ OP 313
ATel #16504; F. D'Ammando (INAF-IRA Bologna) and A. Arbet-Engels (Max-Planck-Institut fur Physik)
on 5 Mar 2024; 10:02 UT
Credential Certification: Filippo D'Ammando (dammando@ira.inaf.it)
Subjects: X-ray, Request for Observations, AGN, Black Hole, Blazar, Quasar
Following the gamma-ray flaring activity of the flat spectrum radio quasar OP 313 (also known as B2 1308+32; z = 0.997, Schneider et al. 2010, AJ, 139, 2360) detected by Fermi-LAT on 2024 February 27 (ATel #16497), Swift observations were performed on 2024 February 28 (Proposer: F. D'Ammando) and March 2 (Proposers: F. D'Ammando and A. Arbet-Engels).
Swift-XRT data were taken in Photon Counting mode for a net exposure of about 4.3 and 1.7 ksec, respectively. The X-ray spectrum (0.3-10 keV) observed on 2024 February 28 and March 2 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 = 1.23 x 10^20 cm^-2, Ben Bekhti N. et al., 2016, A&A, 594, A116) and a photon index of 1.69 +/- 0.11 and 1.62 +/- 0.19, respectively. The corresponding 0.3-10 keV fluxes (corrected for the Galactic absorption) are (6.5 +/- 0.5) x10^-12 erg cm^-2 s^-1 and (5.6 +/- 0.8) x10^-12 erg cm^-2 s^-1, indicating a high flux level with respect to the fluxes observed by XRT during 2007-2021 (i.e. 1.2-4.6 x10^-12 erg cm^-2 s^-1).
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 for making these observations possible, in particular Jamie Kennea as the Swift Observatory Duty Scientist.
