Evolutionary Synthesis Modelling of Young Star Clusters in Merging Galaxies.pdf

Evolutionary Synthesis Modelling of Young Star Clusters in Merging Galaxies Peter Anders, Uta Fritze – v. Alvensleben Universit¨ats-Sternwarte G¨ottingen, Geismarlandstr. 11, 37083 G¨ottingen, Germany Richard de Grijs 2 Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK 0 0 2 Abstract. The observational properties of globular cluster systems (GCSs) are vital tools to investigate the violent star formation histories of their host galaxies. t c This violence is thought to have been triggered by galaxy interactions or mergers. O The most basic properties of a GCS are its luminosity function (number of clusters per luminosity bin) and color distributions. 0 A large number of observed GCS show bimodal color distributions, which can be 1 translated into a bimodality in either metallicity and/or age. An additional uncer- tainty comes into play when one considers extinction. 1 These effects can be disentangled either by obtaining spectroscopic data for the v 3 clusters or by imaging observations in at least four passbands. This allows us then to 2 discriminate between various formation scenarios of GCSs, e.g. the merger scenario 2 by Ashman Zepf, and the multi-phase collapse model by Forbes et. al. 0 Young and metal-rich star cluster populations are seen to form in interacting and 1 merging galaxies. We analyse multiwavelength