Probing the Universe at Radio Wavelengths : from the GMRT to the SKA

Abstract: 
Today, one can study the Universe in different parts of the electromagnetic spectrum, from radio to gamma rays. In this talk, we will see how radio astronomy, which started in the 1940s, has become an integral part of the astronomer's tool-kit. After discussing the functioning of a radio telescope and the basic ideas and techniques in the field, we will explore the range of exotic objects and secrets of the Universe revealed with radio astronomy. As a case study, we will undertake a detailed exploration of our own Giant Metrewave Radio Telescope (GMRT) -- one of the largest metre wavelength radio telescopes in the world today. The GMRT has been in successful operation for the last 12 years, and we will see some of the interesting new results it has produced. The GMRT is presently undergoing a major upgrade that will significantly improve its capability and keep it on the forefront of international research in astrophysics; we will look at the promises this holds out, as well as some of the technological challenges it poses. Looking further into the future, we will also talk briefly about the SKA (Square Kilometre Array) project -- a next generation international radio telescope -- and plans for Indian participation in this mega-project.