X-Ray flare in the Nearby TeV-Detected Blazar 1ES 1727+502
ATel #14276; Bidzina Kapanadze (Ilia State University, Tbilisi, Gerogia; E. Kharadze National Astrophysical Observatory, Abastumani, Georgia)
on 17 Dec 2020; 19:09 UT
Credential Certification: Bidzina Kapanadze (bidzina_kapanadze@iliauni.edu.ge)
Subjects: X-ray, AGN, Blazar
1ES 1727+502 (1Zw 187, z=0.055), a nearby TeV-detected blazar, has been targeted 166 times with X-Ray Telescope onboard Neil Gehrels Swift Observatory during 2010 April 2 - 2020 December 15 with a net exposure of 226 ks. During this period, the 0.3-10 keV count rate varied by a factor of 18, and reached the value of 4.96+/-0.06 cts/s on 2015 November 11 when the source was showing a prolonged X-ray flaring activity (observed mostly in the framework of our ToO requests with different urgencies; see http://www.swift.psu.edu/monitoring /source.php?source=QSOB1727+502 and Kapanadze B. 2015, Atel #8224, #7342). Our current TOO observations (Request Number 14924), performed during December 2-15, revealed a brightness doubling to 2.05+/-0.09 cts/s which nearly equals to the peak of the second strongest historical X-ray flare shown by the source in 2018 May-July. In the framework of one-zone SSC models, a flaring activity of 1ES 1727+502 is also expected in the UV-radio and gamma-ray parts of the electromagnetic spectrum, and intense multiwavelength observations of the source are strongly encouraged for discerning the underlying emission mechanisms and instable processes. XRT is one of the Swift instruments along with Burst Alert Telescope (BAT) and UV/Optical Telescope (UVOT). It is a JET-X Wolter I type telescope, developed jointly by Pennsylvania State University, Brera Astronomical Observatory (OAB) and University of Leicester. Thanks to the unique characteristics, good photon statistics and low background counts of this instrument (in combination with EEV CCD2 detector), we can investigate a flux variability on different time-scales from minutes to years, obtain high-quality spectra for the majority of the observations, derive different spectral parameters, and study their timing behaviour in the 0.3-10 keV range of the electromagnetic spectrum. The Swift Satellite is operated by Pennsylvania State University.
