Properties of Star Clusters -- III: Analysis of 13 FSR Clusters using UKIDSS-GPS and VISTA-VVV

TL;DR

This study confirms the nature of 13 FSR cluster candidates using deep photometric surveys, revealing new insights into their properties, including identifying a potential globular cluster candidate and providing detailed age and distance estimates.

Contribution

The paper presents a homogeneous analysis of 13 FSR clusters using UKIDSS-GPS and VISTA-VVV data, including the discovery of a new cluster and a revised characterization of FSR1716.

Findings

Seven clusters contain pre-main sequence stars.

FSR1716 is a potential globular cluster at 7.3 kpc, 10-12 Gyr old.

Deep photometry led to revised distances and ages.

Abstract

Discerning the nature of open cluster candidates is essential for both individual and statistical analyses of cluster properties. Here we establish the nature of thirteen cluster candidates from the FSR cluster list using photometry from the 2MASS and deeper, higher resolution UKIDSS-GPS and VISTA-VVV surveys. These clusters were selected because they were flagged in our previous studies as expected to contain a large proportion of pre-main sequence members or are at unusually small/large Galactocentric distances. We employ a decontamination procedure of JHK photometry to identify cluster members. Cluster properties are homogeneously determined and we conduct a cross comparative study of our results with the literature (where available). Seven of the here studied clusters were confirmed to contain PMS stars, one of which is a newly confirmed cluster. Our study of FSR1716 is the deepest to date and is in notable disagreement with previous studies, finding that it has a distance of about 7.3kpc and age of 10-12Gyr. As such, we argue that this cluster is a potential globular cluster candidate.