DARK AND LUMINOUS MATTER CONNECTIONS FROM SMOOTHED PARTICLE HYDRODYNAMIC SIMULATIONS OF ISOLATED TRIAXIAL COLLAPSING SYSTEMS

摘要

We performed smoothed particle hydrodynamic simulations of isolated collapsing triaxial systems initially composed of dark matter and gas with cooling, shocks, star formation, and feedback, in particular, self-consistently accounted for. We aim to shed light on the dependence of system evolution on some parameters so far unexplored, such as total mass, initial geometry, and dynamical state. Moreover, the effects of different values of the baryonic-to-total mass ratio have been investigated. We find intriguing connections between dark and luminous matter. The initial properties of the halo drive galaxy formation and evolution. We point out important issues concerning galaxy morphological types. In our framework, spiral galaxies arise only in systems with both a total mass lower than 10~(12) solar mass and a critical value of the baryonic-to-total mass ratio around 0.1. For the same value of such a ratio, the more massive systems host massive elliptical galaxies as a consequence of the stronger bursts of star formation arising into their halos. Higher values of such a ratio provide baryons with lower rotational support so that no constraints on the total mass of the system hosting an elliptical galaxy have been derived.