Description |
Hydrogen is the most abundant element in the Universe. It can be characterized as being in the ionized, neutral atomic (HI), or molecular (H_2) states. Though hydrogen gas is almost completely ionized in the post- re-ionization era, there are still traces of HI locked up inside galaxies, providing fuel for future star formation of the galaxy. HI is therefore a useful probe to study the formation and distribution of large-scale structures in the Universe. I will discuss how different populations of galaxies contribute to the total HI budget, Omega_HI, in the local Universe. I will present how these populations of galaxies make up the total HI mass function, the HI width function, and the HI velocity function. Also, I will describe a model, based on these results, to populate HI in dark matter halos motivated and calibrated from recent observations.
|