General Physical Properties of Blazars

 Blazars are radio-loud active galaxies with their powerful relativistic jets pointed towards the observer. Accordingly, the relativistic amplification of the radiation makes them visible even at extremely large redshift (z>4) and thus they can be used as a cosmological tool to study the evolution of the Universe.

The study of blazars till the beginning of the 21st century was more focused on individual bright objects (e.g., 3C 279, Mrk 421). However, the recent technological advancements in the field of high energy astrophysics, particularly the Swift and the Fermi satellites, have now made it possible to probe the faint end of the blazar population. Motivated by the availability of good quality multi-wavelength (MW) dataset of a large number of blazars, an effort has been made to study a few fundamental physical properties of blazars, such as the accretion-jet connection and the cosmological evolution of relativistic jets. The details of the derived results will be presented with a focus on the role of the latest/upcoming MW missions, e.g., ASTROSAT and e-ASTROGAM.