Multiwavelength studies of TeV blazars

Abstract

Blazars, comprising BL Lacertae objects (BL Lacs; featureless optical spectra) and flat-spectrum radio quasars (FSRQs; strong broad emission lines in optical spectra), are the active galactic nuclei (AGNs) with strong relativistic jets pointing towards the direction of the observer. Their double humped spectral energy distributions (SEDs) extend from radio to very high energy γ-rays. TeV (Teraelectron Volt) blazars, those significantly observed at TeV energies, are mostly the high-frequency peaked BL Lac objects (HBLs), that is, the first hump of their SED peaks at optical to X-ray energy bands. In this thesis, we performed the hard Xray (3-79 keV) and optical variability study of TeV HBLs on intraday timescales (occurring over less than a day) to better understand their fine structures and the underlying emission processes at these frequencies.