About the nature of Mercer 14

作者：Froebrich D^*; Ioannidis G

来源：Monthly Notices of the Royal Astronomical Society, 2011, 418(2): 1375-1381.

DOI：10.1111/j.1365-2966.2011.19589.x

• stars: formation
• ISM: jets and outflows
• open clusters and associations: individual: Mercer 14

We used UK Infrared Telescope (UKIRT) near-infrared (NIR) broad-band JHK photometry, narrow band imaging of the 1-0 S(1) molecular hydrogen emission line and mid-infrared Spitzer IRAC data to investigate the nature of the young cluster Mercer 14. 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 2.5 kpc with an uncertainty of about 10 per cent and can be applied to other young and embedded clusters. Mercer 14 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 4 Myr old and has a line-of-sight extinction of AK = 0.8 mag. Based on the most massive cluster members we find that Mercer 14 is an intermediate mass cluster with about 500 M circle dot.

• 出版日期2011-12