Detection of a bright optical/X-ray flare in FSRQ PKS 0514-459

ATel #14245; F. Jankowsky, S. J. Wagner (LSW Heidelberg), J.-P. Lenain (LPNHE)
on 6 Dec 2020; 01:08 UT
Credential Certification: Stefan J. Wagner (swagner@lsw.uni-heidelberg.de)

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Optical observations of the FSRQ PKS 0514-459 (z=0.194) with the Automatic Telescope for Optical Monitoring (ATOM) in Namibia reveal this blazar in a bright state. Preliminary analysis of measurements performed on the night from 4 to 5 December 2020 (MJD 59187.88) show a peak R magnitude of 13.2. This is 4 magnitudes brighter than the baseline flux measured during the last decade. PKS 0514-459 underwent a steady increase in brightness by 2.8 magnitudes since November 23, 2020 (MJD 59176.10). The optical flare is 2.7 mag brighter than an earlier outburst observed in January 2016, with a coincident Gamma-ray flare reported by the Fermi-LAT collaboration (ATel#8595).
Target-of-Opportunity observation performed with the X-ray Telescope (XRT) of the Neil Gehrels Swift Observatory at MJD 59187.81 resulted in a flux (in the energy range 0.3-10 keV) of (1.3 +/- 0.1) 10^-11 erg cm^-2 s^-1 with a photon index of 1.3. This is the highest flux of PKS 0514-459 ever measured with XRT.
The flare observed in the optical and X-ray band follows a high state of gamma-ray flux recorded in the 100 MeV - 500 GeV band with the Fermi-LAT instrument. Earlier gamma-ray flares had been reported in ATel#8595 and ATel#13705.
Further multifrequency observations of this outburst are encouraged.
ATOM is a 75cm optical telescope located at the H.E.S.S. site in Namibia.
We acknowledge the use of public data from the Swift data archive. We wish to thank the Swift Team for making these observations possible, in particular C. Gronwall as the Swift Observatory Duty Scientist and Brad Cenko for approving these observations.