The Spectral and Variability Characteristics of Blazars and Future with AstroSat

Blazars, a subclass of AGN, being seen directly through the relativistic jet, make a unique and rich sample to understand the physical processes taking place at very close to central super-massive black-hole. The variable emission over very broad spectrum (from radio to TeV), the high \& variable linear polarisation in radio and optical and double humped spectral energy distribution (SED) are used as diagnostics tool to understand the basic physics behind these enigmatic sources. Being very distant and extremely luminous objects, blazars serve as the standard candle to understand the extragalactic background light (EBL) and extragalactic magnetic fields (EGMF). Because of the variable nature of these objects, a large amount of multi-wavelength data observed simultaneously, are essential to perform the consistent studies of blazars. AstroSat, the first indian multi-wavelength (MW) space borne observatory, is certainly going to make a milestone impact to the Astronomy, specially in the fields of the blazars because of its unique MW observational capabilities. 



In this talk, I will be presenting the characterisation of variability and and spectral properties of a blazar FSRQ PKS 1510-089 using approximately 7 years of multi-wavelength data from various resources like Fermi, Swift, SMARTS, MIRO, OVRO etc. I will also be discussing about few preliminary results obtained from AstroSat-SXT during the course of one year and about our plans of blazars studies in near future. As a member of Soft X-Ray Telescope (SXT) calibration team, I will also present the status and the procedures used for various calibrations of the detector and telescope.