Paper detail

Probing FSR star cluster candidates in bulge/disk directions with 2MASS colour-magnitude diagrams

We analyse 20 star cluster candidates projected mostly in the bulge direction ($|\ell|<60^\circ$). The sample contains all candidates in that sector classified by \citet{FSRcat} with quality flags denoting high probability of being star clusters. Bulge contamination in the colour-magnitude diagrams (CMDs) is in general important, while at lower Galactic latitudes disk stars contribute as well. Properties of the candidates are investigated with 2MASS CMDs and stellar radial density profiles (RDPs) built with field star decontaminated photometry. To uncover the nature of the structures we decontaminate the CMDs from field stars using tools that we previously developed to deal with objects in dense fields. We confirm in all cases excesses in the RDPs with respect to the background level, as expected from the method the candidates were originally selected. CMDs and RDPs taken together revealed 6 open clusters, 5 uncertain cases that require deeper observations, while 9 objects are possibly field density fluctuations.