Abstract Details

Name: Abhradeep Roy
Affiliation: Research Scholar
Conference ID: ASI2021_122
Title : Multiwavelength Study of Quiescent States of Brightest Blazars detected by Fermi -LAT
Authors and Co-Authors : Abhradeep Roy (Department of High Energy Physics, Tata Institute of Fundamental Research, Mumbai-400005, India), Sonal R. Patel (Department of Physics, University of Mumbai, Santacruz (East), Mumbai-400098, India), Arkadipta Sarkar (Department of High Energy Physics, Tata Institute of Fundamental Research, Mumbai-400005, India), Anshu Chatterjee (Department of High Energy Physics, Tata Institute of Fundamental Research, Mumbai-400005, India), Varsha R. Chitnis (Department of High Energy Physics, Tata Institute of Fundamental Research, Mumbai-400005, India)
Abstract Type : Poster
Abstract Category : Extragalactic Astronomy
Abstract : The regular monitoring of flat-spectrum radio quasars (FSRQs) in $\gamma$-rays by \textit{Fermi}-Large Area Telescope since past 12 years indicated six sources who exhibited extreme $\gamma$-ray outbursts crossing daily flux of 10$^{-5}$ photons cm$^{-2}$ s$^{-1}$. We obtained nearly-simultaneous multi-wavelength data of these sources in radio to $\gamma$-ray waveband from OVRO, Steward Observatory, SMARTS, \textit{Swift}-mission and \textit{Fermi}-LAT. The time-averaged broadband Spectral Energy Distributions (SEDs) of these sources in quiescent states were studied to get an idea about the underlying baseline radiation processes. We modelled the SEDs using one-zone leptonic synchrotron and inverse-Compton emission scenario from broken power-law electron energy distribution inside a spherical plasma blob, relativistically moving down a conical jet. The model takes into account inverse-Compton scattering of externally and locally originated seed photons in the jet. The big blue bumps visible in quiescent state SEDs helped to estimate the accretion disk luminosities and central black hole masses. We found a correlation between magnetic field inside the emission region and the ratio of emission region distance to disk luminosity, which implies that magnetic field decreases with increase in emission region distance and decrease in disk luminosity, suggesting a disk-jet connection. High energy index of the electron distribution was also found to be correlated with observed $\gamma$-ray luminosity as $\gamma$-rays are produced by high energy particles. In most cases, kinetic power carried by electrons can account for jet radiation power as jets become radiatively inefficient during quiescent states.