Assessing the physical reality of Milky Way open cluster candidates by A. E. Piatti et al. on Tuesday 29 November

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 diagram, by employing extreme deconvolution Gaussian mixture

models. We treated these objects as real open clusters and derived their

fundamental properties with their associated intrinsic dispersions by exploring

the parameter space through the minimization of likelihood functions on

generated synthetic colour-magnitude diagrams (CMDs). The intrinsic dispersions

of the resulting ages turned out to be much larger than those usually obtained

for open clusters. Indeed, they resemble those of ages and metallicities of

composite star field populations. We also traced their stellar number density

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 motion plane and some hint for similar distances, we

concluded that they are possibly sparse groups of stars.

arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15483v1