|Name: Kanan Kumar Datta
Affiliation: Presidency University, Kolkata
Conference ID: ASI2017_1241
Title : Probing the universe with the HI 21cm line
Authors and Co-Authors : NA
Abstract Type :
Abstract Category : Plenary
Abstract : A period of major changes in the Universe took place between âˆ¼0.2 and âˆ¼ 2 billion years after the big bang at the time when the first galaxies and supermassive black holes were forming. The onset of first sources of light which marked the end of the â€˜dark agesâ€™ and changed the IGM thermal state is often termed as â€˜cosmic dawnâ€™. Subsequent period when the neutral hydrogen (HI) was ionized is popularly known as the epoch of reionization (EoR). Unfortunately, these landmark events remain largely unexplored. Radio interferometric observations of redshifted HI 21-cm radiation are considered to constitute the most promising tool to probe the reionization epoch. In my presentation, I shall start with a brief introduction about the cosmic dawn, reionization epoch and HI 21-cm radiation from these epochs. Subsequently, I shall discuss recent experimental efforts and various observational strategies being/will be adopted by ongoing or upcoming radio interferometric experiments. Next I shall focus on statistical quantities that will be measured by these experiments and present results from recent simulations. We shall then discuss about methods for detecting reionizing sources (e.g galaxies, quasars) individually. Finally, we shall discuss about the most ambitious upcoming project i.e, the SKA and some related activities being carried out in India.