Authors: Bradley C Whitmore
Publish Date: 2009/09/15
Volume: 324, Issue: 2-4, Pages: 163-169
Abstract
We report on the development of a framework for understanding the demographics of star cluster systems The model incorporates a universal initial powerlaw mass function selected formation histories selected disruption laws and a convolution with common artifacts and selection effects found in observational data An important component of our model is the use of a ‘twostage’ disruption process with a very high ‘infant mortality’ rate for the clusters with ages less than ≈108 yr ie roughly 80 to 90 are lost each factor of ten in time τ independent of mass and twobody relaxation which becomes the dominant disruption mechanism at older ages preferentially removing the lowermass clusters Stars from the dissolved clusters form the field population and hence the galaxies themselves We also report on efforts to distinguish stars from clusters in the Antennae galaxies allowing us to show that the powerlaw luminosity function for star clusters extends roughly three magnitudes fainter than previously demonstrated contrary to reports that there is a turnover Finally we briefly show that while triggered star formation in several regions of the Antennae is relatively mild ie producing roughly 10 as many stars as in the previous generation in some regions there can be an amplification of a factor of four or more
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