AstroSat observation of the HBL 1ES 1959+650 during its October 2017 flaring
Abstract
We present the results of the X-ray flaring activity of 1ES 1959+650 during 2017 October 25-26 using AstroSat observations. The source was variable in the X-ray. We investigated the evolution of the X-ray spectral properties of the source by dividing the total observation period (~130 ks) into time segments of 5 ks, and fitting the Soft X-ray focusing Telescope and Large Area X-ray Proportional Counter spectra for each segment. Synchrotron emission of a broken power-law particle density model provided a better fit than the log-parabola one. The X-ray flux and the normalized particle density at an energy less than the break one were found to anticorrelate with the index before the break. However, a stronger correlation between the density and index was obtained when a delay of ~60 ks was introduced. The amplitude of the normalized particle density variation |Δnγ/nγ| ~ 0.1 was found to be less than that of the index ΔΓ ~ 0.5. We model the amplitudes and the time delay in a scenario where the particle acceleration time-scale varies on a time-scale comparable to itself. In this framework, the rest-frame acceleration time-scale is estimated to be ~1.97 × 105 s and the emission region size to be ~6.73 × 1015 cm.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- July 2021
- DOI:
- arXiv:
- arXiv:2104.13472
- Bibcode:
- 2021MNRAS.504.5485S
- Keywords:
-
- galaxies: active;
- BL Lacertae objects: general;
- BL Lacertae objects: individual: 1ES 1959+650;
- galaxies: jets;
- X-rays: galaxies;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 13 pages, 7 figures, 3 tables. Accepted for publication in MNRAS