Cosmology Seminar: Hamsa Padmanabhan

Hamsa Padmanabhan is a postdoctoral Tomalla Fellow at the ETH Zurich

A halo model for cosmological neutral hydrogen

The evolution of neutral hydrogen (HI) across redshifts is a powerful probe of cosmology, large scale structure in the universe and the intergalactic medium. We build an analytical halo model to describe the distribution of HI in the post-reionization universe (z ~ 5 to 0). We obtain the best-fitting parameters from a rich sample of observational data: low redshift 21-cm emission line studies, intermediate redshift intensity mapping experiments, and higher redshift Damped Lyman Alpha (DLA) observations.  Our model describes the abundance and clustering of neutral hydrogen across redshifts 0 - 5, and is a useful tool for investigating different aspects of galaxy evolution as well as in the current and future HI intensity mapping experiments. I will also discuss extensions to the model for carbon monoxide intensity mapping at moderate redshifts.

Organizer

Benjamin Racine and Bridget Falck
Published May 16, 2017 10:26 AM - Last modified May 16, 2017 1:38 PM