Intensity Mapping

We are using the technique of “intensity mapping”, in which the combined HI emission signals of large numbers of galaxies are averaged together in a wide-area blind survey, to study the neutral gas content of the Universe at a range of cosmic times. Our radio survey data are being combined with additional information from optical redshift surveys and from galaxy simulations. The cross-correlation of redshifted 21cm intensity with galaxies holds the promise of measuring hydrogen at high redshift, and studying the distribution of HI in galaxies. This first phase of the project will include modelling of these data sets, and is primarily Evolving Universe science. Our studies of current data sets will pave the way for future studies of the auto-correlation of redshifted 21cm intensity for cosmological application including BAO. The second phase lies within the Dark Theme.

HIPASS HI and 6dF correlation.
A plot of the correlation between HIPASS neutral hydrogen data and 6dFGS optical redshift data as a function of the spatial offset between the data sets. The plot was the first to demonstrate the potential of intensity mapping to statistically extract signals from HI radio data (Pen et al. 2009)

CAASTRO Researchers in this Project
Professor Lister Staveley-Smith  (Project Leader) Professor Stuart Wyithe  (Project Leader)
 CAASTRO Member  Node
 Associate Professor Chris Blake  Swinburne University of Technology
 Associate Professor Tamara Davis  The University of Queensland
 Dr. Hansik Kim  University of Melbourne
 Professor Chris Power  University of Western Australia
 Dr. Jonghwan Rhee  University of Western Australia
 Dr. Laura Wolz  University of Melbourne
 Professor Stuart Wyithe  University of Melbourne