Prof. Hum Chand

Various observational probes of the central engine and environment of AGN, at different length scales, play a key role in our understanding of the formation and evolution of proto-galaxy at high redshift. In this context, we will summarise a few of our recent experiments, such as; (i) To probe the excess H-I density around the quasars in 1-10Mpc scale by studying proximity effect in a large sample of quasars pairs having separation <1.5arcmin; (ii) On the nature of extreme outflows having offset velocity as high as 0.1c, probing length scale of about 100pc, based on studies of broad absorption line (BAL) in a large sample of "Appearing and Disappearing" BAL-QSOs. Further, we will also discuss our ongoing experiment to constrain the distance of Broad Line Region (BLR) around the central engine of AGNs by using the techniques of photometric reverberation mapping of a sample of low luminous AGNs (L< 10^43 erg/s), so as to estimate their Blackhole mass as well as to test the Virial "L-R" scaling relation in this low luminosity regime. Finally, in the context of X-ray emission coming from very close to the AGN central engine, we will also highlight our recent investigation of a comparative study of X-ray and optical properties a sample of Narrow-line Seyfert-I and Broad-line Seyfert-I galaxies, along with near-future improvement expected from the ground and space-based facilities.