Gaia EDR3 view on galactic globular clusters

By Eugene O. Vasiliev, H. Baumgardt. Monthly notices of the Royal Astronomical Society, 2021

198 citations recorded by the source corpus.

We use the data from Gaia Early Data Release 3 (EDR3) to study the kinematic properties of Milky Way globular clusters. We measure the mean parallaxes and proper motions (PM) for 170 clusters, determine the PM dispersion profiles for more than 100 clusters, uncover rotation signatures in more than 20 objects, and find evidence for radial or tangential PM anisotropy in a dozen richest clusters. At the same time, we use the selection of cluster members to explore the reliability and limitations of the Gaia catalogue itself. We find that the formal uncertainties on parallax and PM are underestimated by $10{-}20{{\ \rm per\ cent}}$ in dense central regions even for stars that pass numerous quality filters. We explore the spatial covariance function of systematic errors, and determine a lower limit on the uncertainty of average parallaxes and PM at the level 0.01 mas and 0.025 mas yr$^{-1}$ , respectively. Finally, a comparison of mean parallaxes of clusters with distances from various literature sources suggests that the parallaxes for stars with $G>13$ (after applying the zero-point correction suggested by Lindegren et al.) are overestimated by $\sim 0.01\pm 0.003$ mas. Despite these caveats, the quality of Gaia astrometry has been significantly improved in EDR3 and provides valuable insights into the properties of star clusters.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/0ab8eddbf79ea8963c5b11d13c1620e5bdad198d

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Citations in the corpus

The Early Data Release of the Dark Energy Spectroscopic Instrument (2023, background): “Targets were selected to be “ likely ” members of Milky Way GCs. “ Likely, ” here, corresponds to a membership probability of P > 0.3, with P as de ﬁ ned in Vasiliev & Baumgardt ( 2021 ) .”
Measurements of the Hubble Constant: Tensions in Perspective (2021, unknown): “As a 5 More recently, Baumgardt & Vasiliev (2021) obtained a 1% distance to ω Cen by combining CMD fitting, RR Lyrae, and DEBs, in addition to the new Gaia EDR3 distance, corrected for the systematic offset.”