Looking at the relation between haloes and galaxies under the lens

Understand

We use an empirical approach to model the stellar mass of galaxies according to their host dark-matter haloes and subhaloes ('HASH'), where each galaxy resides in a subhalo taken from a large N-body cosmological simulation.

• This approach allows us to study the mass relation between subhaloes and galaxies (MR) using: the weak lensing signal (WL), the two point auto-correlation function (CF), and the stellar mass function of galaxies (SMF).
• Our method is based on modeling the lensing signal directly from the cosmological simulation, and should thus be more accurate than other methods based on analytic halo models.
• We find that the WL does not provide a strong constraint on the MR, allowing for more than a factor of 10 freedom in the subhalo mass of central galaxies, for a given stellar mass.