An analysis of the evolving comoving number density of galaxies in hydrodynamical simulations

Understand

The cumulative comoving number-density of galaxies as a function of stellar mass or central velocity dispersion is commonly used to link galaxy populations across different epochs.

• By assuming that galaxies preserve their number-density in time, one can infer the evolution of their properties, such as masses, sizes, and morphologies.
• However, this assumption does not hold in the presence of galaxy mergers or when rank ordering is broken owing to variable stellar growth rates.
• We present an analysis of the evolving comoving number density of galaxy populations found in the Illustris cosmological hydrodynamical simulation focused on the redshift range $0\leq z \leq 3$.