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: (1) large-scale (100pc-100kpc) SPH simulations on density and temperature evolution of gas in interacting/merging galaxies and (2) small-scale ones on the effects of high gas pressure of 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 ($\sim$ $10^5$ $\rm k_{\rm B}$ K $\rm cm^{-3}$), in particular, in the tidal tails or the central regions of mergers. We also find that GMCs can collapse to form super star clusters within an order of $10^7$ yr owing to the strong compression by the high presser ISM in mergers.