High Energy Physics Seminars

Multiwavelength Study of Quiescent States of Brightest Fermi Blazars.

by Abhradeep Roy (DHEP, TIFR)

Thursday, May 6, 2021 from to (Asia/Kolkata)
at TIFR, Mumbai ( D406 )
The regular monitoring of flat-spectrum radio quasars (FSRQs) in γ-rays by Fermi-Large Area Telescope (Fermi-LAT) for the past 12 years indicated six sources who exhibited extreme γ-ray outbursts crossing daily flux of 10 -5 photons/cm2 /s. We obtained nearly-simultaneous multi-wavelength data of these sources in radio to γ-ray waveband from OVRO, Steward Observatory, SMARTS, Swift-mission and FermiLAT. 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 electron distribution inside a spherical plasma blob, relativistically moving down a conical jet. We found a correlation between the magnetic field inside the emission region and the ratio of emission region distance to disk luminosity, suggesting a disk-jet connection. The high energy index of the electron distribution was also found to be correlated with observed γ-ray luminosity as γ-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.
I shall also describe briefly my work on the SiPM camera and future plans.