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 October 25-26, 2017 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 ($\sim 130$ ksecs) into time segments of 5 ksecs, and fitting the SXT and LAXPC 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 normalised particle density at an energy less than the break one, were found to anti-correlate with the index before the break. However, a stronger correlation between the density and index was obtained when a delay of $\sim 60$ ksec was introduced. The amplitude of the normalised particle density variation $|\Delta n_{\gamma }/n_{\gamma }|\sim 0.1$ was found to be less than that of the index $\Delta \Gamma \sim 0.5$. 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 $\sim 1.97\times 10^5$ secs and the emission region size to be $\sim 6.73\times 10^{15}$ cms.

13 pages, 7 figures, 3 tables. Accepted for publication in MNRAS

References in corpus (12)

• Rapid Variability of Blazar 3C 279 during Flaring States in 2013-2014 with Joint Fermi-LAT, NuSTAR, Swift, and Ground-Based Multi-wavelength Observations
• Large Area X-ray Proportional Counter (LAXPC) Instrument on AstroSat and Some Preliminary Results from its performance in the orbit
• AstroSat/LAXPC reveals the high energy variability of GRS 1915+105 in the chi class
• A multi-zone model for simulating the high energy variability of TeV blazars
• Long-Term X-Ray and TeV variability of Mrk 501
• Investigating Broadband Variability of the TeV Blazar 1ES 1959+650
• AstroSat/LAXPC observation of Cygnus X-1 in the hard state
• Clues on High Energy Emission Mechanism from Blazar 3C 454.3 during 2015 August Flare
• Multiwavelength Observations of 1ES 1959+650, One Year After the Strong Outburst of 2002
• Unfolding the X-ray Spectral Curvature of Mkn 421 for Further Clues
• Unravelling the unusually curved X-ray spectrum of RGB J0710+591 using AstroSat observations
• Curvit: An open-source Python package to generate light curves from UVIT data

Cited by in corpus (5)

• Understanding the X-ray spectral curvature of Mkn 421 using broadband AstroSat observations
• X-ray Studies of Blazar 1ES 1959+650 Using SWIFT & XMM-NEWTON Satellite
• Photohadronic interpretation of the different incarnation of 1ES 2344+514
• Correlated Short-Timescale Hard-Soft X-ray Variability of the Blazars Mrk 421 and 1ES 1959+650 using $\text{AstroSat}$
• X-ray Observations of 1ES 1959+650 in its high activity state in 2016-2017 with AstroSat and Swift