HI-selected Galaxies in Hierarchical models of Galaxy Formation and Evolution

This poster presents the main results of a statistical study of HI-selected galaxies based
on six different semi-analytic models, all run on the same
cosmological N-body simulation. One of these models includes an
explicit treatment for the partition of cold gas into atomic and
molecular hydrogen. All models considered agree nicely with the
measured HI mass function in the local Universe and with the
measured scaling relations between HI and galaxy stellar mass.
Most models also reproduce the observed 2-point correlation
function for HI rich galaxies, with the exception of one model
that predicts very little HI associated with galaxies in haloes
above 10^12 Msun. We investigated the influence
of satellite treatment on the final HI content and found that
it introduces large uncertainties at low HI masses. We found
that the assumption of instantaneous stripping of hot gas in
satellites does not translate necessarily in lower HI masses.
We demonstrate that the assumed stellar feedback, combined
with star formation, also affect significantly the gas content
of satellite galaxies. Finally, we also analyse the origin of
the correlation between HI content of model galaxies and the
spin of the parent haloes.

Zoldan et al., 2016, MNRAS, 465, 2236