Multi-wavelength Variability and Quasi Periodic Oscillations in Blazars
Tsung-Dao Lee Institute/S4F-SW - Open Area
Tsung-Dao Lee Institute
Host: Sandeep Kumar Mondal
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Abstract：
This is the age of multi-wavelenth (MW) time domain astronomy in which the transient astronomical sources are of great interest due to their rapid change in flux, spectra and polarization. Simultaneous MW observation of a particular transient source over an extended period of time has importance to understand the emission mechanism in different electromagnetic (EM) bands. Blazars are among one of the most favourite astronomical transient objects, because they emit radiation in the complete EM spectrum, and their flux, spectra and polarization are highly variable.
In this talk, I will present a glimpse of various science projects of blazars which represent flux, spectra and polarization variabilities in blazars on diverse timescales, sometimes in a single EM band and sometimes simultaneously in MW. I will also present a few key results of detection of quasi periodic oscillations (QPOs) in blazars time series data. I will briefly discuss possible emission mechanisms responsible for observed variability and QPOs.
Biography:
Prof. Alok Chandra Gupta is a Senior Professor at Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital, India. Prof. Gupta did Ph.D. in 1999 from DDU Gorakhpur University, India and 1999 - 2006 worked as a postdoctoral fellow / visiting fellow in various institutes in India, Germany and France. In 2006 - 2007, he was a visiting professor in Yunnan Astronomical Observatory, Kunming, China and then at Center for Astrophysics, Guangzhou University, Guangzhou, China. In January 2008 joined as a permanent faculty member in ARIES, Nainital.
Prof. Gupta mainly works on various aspects of Multi-wavelength observational properties of Blazars which include flux, spectral, and polarization variability on diverse timescales. He is also extensively working on the search for quasi periodic oscillations (QPOs) in blazars in different electromagnetic bands light curves. Till date he has published about 200 research papers in refereed international journals which have more than 7000 citations and his H-index is 51.
Prof. Gupta has got PIFI fellowship in shanghai astronomical observatory (SHAO), Shanghai in 2016 and visited there several times including 2 one year sabbaticals in 2016 - 2017 and 2022 - 2023. He has again been awarded a PIFI fellowship at Xinjiang Astronomical Observatory (XAO), Urumqi, China and is currently visiting XAO, Urumqi.
