Young Massive Clusters in Normal Galaxies

Abstract.

Luminous young star clusters are found not only in starbursts and merger galaxies, but also in normal spiral galaxies with high star formation rates. This suggests a continuum of cluster properties and a universality in cluster formation mechanisms, which is likely to also include classical “globular” clusters. Comparison with existing data for a sample of galaxies shows that the luminosities of the brightest clusters are consistent with random sampling from a power-law luminosity function, suggesting that statistical effects can account for some of the apparent differences between cluster populations in various environments. It is still unclear to what extent the underlying mass distribution of young stellar clusters might be affected by physical properties of the parent galaxies.