X-Ray Re-Flare in 1ES 1101-232
ATel #17219; Bidzina Kapanadze (Ilia State University, Tbilisi, Georgia; National Astrophysical Observatory, Abastumani, Georgia)
on 4 Jun 2025; 20:05 UT
Credential Certification: Bidzina Kapanadze (bidzina_kapanadze@iliauni.edu.ge)
The southern TeV-detected blazar 1ES 1101-232 (z=0.186) has been observed 94 times with the X-Ray Telescope (XRT) onboard the Neil Gehrels Swift Observatory since 2005 June 30. These observations showed a strong flaring activity several times, with the highest-amplitude flare and the highest historical XRT-band state during 2023 November--2024 January (recorded during the Swift-TOO observations triggered by us; see Kapanadze B., ATels #16322 and #16396). Since 2025 May 14, the source was visited 5 times by Swift-XRT (in the framework of our TOO Request Number 22536) and this monitoring revealed an onset of another long-term X-ray flare: initially, the brightness was declined by ~20\% and then showed a gradual increase by ~30% in the course of the last three observation to the 0.3-10 keV count rate of 2.59+/-0.08 cts/s, shown during the last XRT visit to the source (performed on June 3). The latter is ~40% higher than the mean rate from all XRT observations of 1ES 1101-232. Since the source is in X-ray flaring state and a further brightening may occur, as well as enhanced multiwavelength activity is predicted also in other spectral ranges in the framework of one-zone SSC scenario, we strongly encourage intense MWL observations with the space and ground-based instruments.
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.
