About the nature of Mercer14

TL;DR

This study investigates Mercer14, a young embedded star cluster, using multi-wavelength infrared observations to determine its distance, age, and star formation activity, revealing it as a less than 4-million-year-old, intermediate-mass cluster with active star formation.

Contribution

It introduces a new method for estimating distances to young embedded clusters using star counts and galaxy models, applied here to Mercer14.

Findings

Distance of 2.5 kpc with 10% uncertainty

Signs of ongoing star formation including molecular outflows

Cluster mass approximately 500 solar masses

Abstract

We used 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% 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 4Myrs old and has a line of sight extinction of A_K=0.8mag. Based on the most massive cluster members we find that Mercer14 is an intermediate mass cluster with about 500Mo.