Abstract Details
| Name: Navpreet Kaur Affiliation: Research Student Conference ID: ASI2016_783 Title : Multiwavelength study of recent flaring activity in HBL 1ES 1959+650 Authors and Co-Authors : Navpreet Kaur (PRL), Sameer (PRL), Sunil Chandra (TIFR), KS Baliyan (PRL), S Ganesh (PRL) PRL:Physical Research Laboratory, Ahmedabad, India TIFR:Tata Institute of Fundamental Research, Mumbai, India Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : Since the central engine, responsible for huge energy output, of AGNs is too compact to be spatially resolved with today's facilities, variability in flux across the electromagnetic spectrum play a crucial role in understanding the structure of these sources and the physical processes responsible for their emissions. We observed relatively less studied high energy peaked blazar, 1ES 1959+650, from Mt Abu 1.2m telescope during October - December 2015 in optical. The source has shown tremendous activity in X-ray and Gamma-rays as reported via several Astronomical Telegrams. In X-ray, it seems to consistently break earlier records with brightest ever state with 22.97 counts/s (equivalent flux 9.35 times 10^{-10} erg cm{^-2} s^{-2}) on 26 December 2016 (Atel# 8468). The activity started first in high energy gamma-rays which was immediately picked up at lower energies: X-ray and UV - optical. In optical R band, 1ES 1959+650 brightened from 14.30 (October 23, 2015) to 14.10 (November 18). It reached R~ 14.05 mag on December 5, 2015. Since then, it has gone fainter as per our observations upto December 14. We have also monitored the source for more than two hours over few nights to check for intra-night variability but it was not found very significant (< 3-sigma level). To understand multiwavelength behaviour of the source during the flare of October - December 2015, we have analysed X-ray, UVOT (Swift) and Gamma-ray (Fermi) data for the period. Preliminary results show strong correlation between all the light-curves corresponding to R-band, UVOT bands, X and gamma-ray flux. The main outburst, starting at about MJD 57270 appears to be half-way albeit seems to have peaked. The details of the study will be presented at the meeting. |