Abstract
We present our new, fully-automated method to detect and measure the ages of
star clusters in nearby galaxies, where individual stars can be resolved. The
method relies purely on statistical analysis of observations and Monte-Carlo
simulations to define stellar overdensities in the data. It decontaminates the
cluster color-magnitude diagrams and, using a revised version of the Bayesian
isochrone fitting code of Ramirez-Siordia et al., estimates the ages of the
clusters. Comparisons of our estimates with those from other surveys show the
superiority of our method to extract and measure the ages of star clusters,
even in the most crowded fields. An application of our method is shown for the
high-resolution, multi-band imaging of the Large Magellanic Cloud. We detect
4850 clusters in the 7 deg2 we surveyed, 3451 of which have not been reported
before. Our findings suggest multiple epochs of star cluster formation, with
the most probable occurring ~310 Myr ago. Several of these events are
consistent with the epochs of the interactions among the Large and Small
Magellanic Clouds, and the Galaxy, as predicted by N-body numerical
simulations. Finally, the spatially resolved star cluster formation history may
suggest an inside-out cluster formation scenario throughout the LMC, for the
past 1 Gyr.
Description
[1707.02311] A novel method to automatically detect and measure the ages of star clusters in nearby galaxies: Application to the Large Magellanic Cloud
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