Assessing the physical reality of Milky Way open cluster candidates

A.E. PIATTI ET AL.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2023 vol. 518 p. 6216 - 6222

0035-8711

We report results on the analysis of eleven new Milky Way open cluster candidates,recently discovered from the detection of stellar overdensities in the Vector Point di-agram, by employing extreme deconvolution Gaussian mixture models. We treatedthese objects as real open clusters and derived their fundamental properties with theirassociated intrinsic dispersions by exploring the parameter space through the min-imization of likelihood functions on generated synthetic colour-magnitude diagrams(CMDs). The intrinsic dispersions of the resulting ages turned out to be much largerthan those usually obtained for open clusters. Indeed, they resemble those of ages andmetallicities of composite star field populations. We also traced their stellar numberdensity profiles and mass functions, derived their total masses, Jacobi and tidal radii,which helped us as criteria while assessing their physical nature as real open clusters.Because the eleven candidates show a clear gathering of stars in the proper motionplane and some hint for similar distances, we concluded that they are possibly sparsegroups of stars.