About the nature of Mercer14

We used UK Infrared Telescope (UKIRT) near-infrared (NIR) broad-band JHK photometry, narrow band imaging of the 1-0S(1) molecular hydrogen emission line and mid-infrared Spitzer IRAC data to investigate the nature of the young cluster Mercer14. Foreground star counts in decontaminated NIR photometry and a comparison with the Besancon Galaxy Model are performed to estimate the cluster distance. This method yields a distance of 2.5kpc with an uncertainty of about 10 per cent and can be applied to other young and embedded clusters. Mercer14 shows clear signs of ongoing star formation with several detected molecular hydrogen outflows, a high fraction of infrared excess sources and an association to a small gas and dust cloud. Hence, the cluster is less than 4Myr old and has a line-of-sight extinction of AK=0.8mag. Based on the most massive cluster members we find that Mercer14 is an intermediate mass cluster with about 500Mâ??. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.