Measurements of the angular momentum–mass relations in the Simba simulation.

We present measurements of the specific angular momentum content (j) of galaxies drawn from the Simba cosmological hydrodynamic simulations. For the stellar, H i and baryonic matter components we demonstrate the existence of extremely tight relations between j and the mass contained within the radius at which the H i mass surface density decreases to 1 M ⊙ pc−2. These relations are broadly consistent with a variety of empirical measurements. We confirm the observational result that the scatter in the stellar j – M relation is driven largely by H i content, and measure the dependence of its scatter on the deviations of galaxies from other important scaling relations. For a given stellar mass, H i -rich/poor galaxies have more/less-than-average stellar specific angular momentum. A similar, yet weaker, correlation exists for H i mass fraction. Overall, our results demonstrate the utility of the Simba simulations as a platform for understanding and contextualising the data and results from forthcoming large galaxy surveys. [ABSTRACT FROM AUTHOR]