We use the Advanced Camera for Surveys on the Hubble Space Telescope to study the rich population of young massive star clusters in the main body of NGC 3256 , a merging pair of galaxies with a high star formation rate ( SFR ) and SFR per unit area ( \Sigma _ { SFR } ) .
These clusters have luminosity and mass functions that follow power laws , dN / dL \propto L ^ { \alpha } with \alpha = -2.23 \pm 0.07 , and dN / dM \propto M ^ { \beta } with \beta = -1.86 \pm 0.34 for \tau < 10 Myr clusters , similar to those found in more quiescent galaxies .
The age distribution can be described by dN / d \tau \propto \tau ^ { \gamma } , with \gamma \approx - 0.67 \pm 0.08 for clusters younger than about a few hundred million years , with no obvious dependence on cluster mass .
This is consistent with a picture where \sim 80 \% of the clusters are disrupted each decade in time .
We investigate the claim that galaxies with high \Sigma _ { SFR } form clusters more efficiently than quiescent systems by determining the fraction of stars in bound clusters ( \Gamma ) and the CMF/SFR statistic ( CMF is the cluster mass function ) for NGC 3256 and comparing the results with those for other galaxies .
We find that the CMF/SFR statistic for NGC 3256 agrees well with that found for galaxies with \Sigma _ { SFR } and SFRs that are lower by 1 - 3 orders of magnitude , but that estimates for \Gamma are only robust when the same sets of assumptions are applied .
Currently , \Gamma values available in the literature have used different sets of assumptions , making it more difficult to compare the results between galaxies .