Extraction of globular clusters members with Gaia DR2 astrometry

Abstract

In this work we present a method to identify possible members of globular clusters using data from Gaia DR2. The method consists of two stages: the first one based on a clustering algorithm, and the second one based on the analysis of the projected spatial distribution of stars with different proper motions. In order to confirm that the clusters members extracted by the method correspond to actual globular clusters, the spatial distribution, the vector point diagram of the proper motions and the colour-magnitude diagrams are analysed. We apply the developed method to eight clusters: NGC 1261, NGC 3201, NGC 6139, NGC 6205, NGC 6362, NGC 6397, NGC 6712 and Palomar 13; we show the number of members extracted, the mean proper motions derived from them and finally we compare our results with other authors. In order to analyse the efficiency of the extraction method we perform an estimation of the completeness and the degree of contamination of the extracted members.

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Cited by in corpus (14)

• BALRoGO: Bayesian Astrometric Likelihood Recovery of Galactic Objects -- Global properties of over one hundred globular clusters with Gaia EDR3
• CCD \emph{VI} time-series of the extremely metal poor globular cluster M92: revisiting its variable star population
• Isochrone fitting of Galactic globular clusters -- II. NGC6205 (M13)
• The globular cluster M10: Reassessment of stellar membership, distance and age using its variable and HB stars
• A new photometric study of M14 (NGC 6402): An interpretation of the Horizontal Branch and beyond
• A vindication of the RR Lyrae Fourier light curve decomposition for the calculation of metallicity and distance in globular clusters
• A time-series VI study of the variable stars of the globular cluster NGC 6397
• Ultraviolet Imaging Telescope (UVIT) observation of the Galactic Globular Cluster NGC 7492
• NGC 6712: the variable star population of a tidally disrupted globular cluster
• Study of UV bright stellar populations in the globular cluster NGC 1261 using AstroSat
• A new visit to the variable stars in M56 and its colour magnitude diagram structure
• Detailed analysis of the variable star population in the globular cluster NGC 7006
• RR Lyrae stars in the globular cluster Palomar 2
• The variable stars in the field of NGC 6139: A critical approach to their reddening and membership