Abstract Details

Name: KRISHNA MOHANA A
Affiliation: Manipal Centre for Natural Sciences, MAHE, Manipal
Conference ID: ASI2020_261
Title : Understanding the dynamics of blazar 3C 66A
Authors and Co-Authors : Krishna Mohana A and Debbijoy Bhattacharya
Abstract Type : Poster
Abstract Category : Extragalactic Astronomy
Abstract : Blazars, a subclass of active galactic nuclei (AGN) are known to exhibit both rapid as well as long-term variations in different waveband. The relativistic jet of them makes a very small angle with the line-of-sight of the observer. Hence, their emission is jet dominated and significantly Doppler boosted. One of the blazar 3C 66A exhibits a short-term variability (Intra-day) and also long-term variations (~ order of months) in optical band. From the 11 years of ɣ-ray lightcurve, we noticed the presence of two long-term activity states with noticeable difference in average ɣ-ray flux. Moreover, such change occurred over a timescale of ~month. The first activity state was for ~3 years followed by a change in the baseline activity during June 2011, which further continued for the next 8 years. Also, a similar change in baseline flux was noticed in optical band. Change of long-term averaged baseline flux in optical and ɣ-ray bands with such short transition time scale is quite unusual and demands further investigations to understand the underlying physical cause. In this work we carry out a systematic multi-band study of the source 3C 66A utilizing observations in ɣ-ray band from Fermi-LAT, X-ray and UV band from SWIFT-XRT and UVOT, optical data from Steward observatory and other available archival data. The preliminary results of our study is presented here.