Research description:

Radio Galaxies and Quasars:
Powerful radio sources reside in massive galaxies, and finding radio galaxies at earlier cosmological epochs is important to understand the evolution of galaxies. Host galaxies of high redshift radio sources show very high star formation rates and also large reservoirs of dust and gas. These are believed to be the precursors of massive elliptical galaxies in the local Universe. Low frequency radio spectra provide the most efficient method to find these high redshift radio galaxies (HzRGs). We have been using the low frequency data from GMRT, particularly at 150 MHz, to search for steep spectrum radio sources which are good candidates for these HzRGs. We have conclusively shown that known HzRGs represent the tip of the ice-berg; "normal population" of HzRGs, which are yet to be discovered, are well within the reach of current generation instruments like GMRT. From one of the deep fields, we produced a list of about 100 strong candidates for HzRGs. These candidates will be followed up with large optical telescopes in the coming years. We are also re-observing several of these fields at 325 MHz. Such deep radio surveys have long lasting value; they can be used to study evolution of radio sources from highest luminosity to faintest end of star-burst galaxies.

TIFR-GMRT-Sky Survey:
The TIFR GMRT Sky Survey (TGSS) is an all sky survey, covering an area of about 90% of the sky, from declination of -55 degree to +90 degree, at 150 MHz using the GMRT (http://tgss.ncra.tifr.res.in) This survey is expected to fulfill a prominent goal of the GMRT and will prove to be a major database for multi-wavelength astronomy. TGSS will yield a large number of high-redshift radio galaxy candidates, which will be systematically followed up with optical telescopes. I am also interested in searching for new giant radio sources, double-double radio sources and relic radio sources in the TGSS.