Star Clusters and Galactic Chemodynamics: Implosive Formation of Super Star Clusters

Abstract

We numerically investigate dynamical and chemical properties of star clusters (open and globular clusters, and ‘super star clusters’, SSC) formed in interacting/merging galaxies. The investigation is two-fold: (a) large-scale (100 pc–100 kpc) SPH simulations on density and temperature evolution of gas in interacting/merging galaxies and (b) small-scale simulations on the effects of the high gas pressure of the ISM on the evolution of molecular clouds. We find that the pressure of ISM in merging galaxies can become higher than the internal pressure of GMCs (~10⁵k _B K cm^–3), in particular, in the tidal tails or the central regions of mergers. We also find that GMCs can collapse to form SSCs within an order of 10⁷ yr due to the strong compression by the high-pressure ISM in mergers.