WFPC2 Observations of the Double Cluster NGC 1850 in the Large Magellanic Cloud

Abstract

HST-WFPC2 optical and ultraviolet imaging observations of the young double cluster NGC 1850 in the LMC are presented. The main cluster, NGC 1850A, is a globular-like cluster and has an age of 50+/-10 Myr, while the subcluster, NGC 1850B, which is more loosely distributed, is very young at 4.3 +/- 0.9 Myr. Its young age is confirmed by the detection of a pre-main-sequence population of stars associated to it. The two clusters have considerably different IMF slopes, with the main cluster having a flat slope [f(m) is proportional to m^-1.4+/-0.2^] and the young cluster a much steeper one [f(m) is proportional to m^-2.6+/- 0.1] The LMC field star population displays a broad range of ages, from ~0.5 Gyr up to more than 4 Gyr.