The dynamics of the γ Vel cluster and nearby Vela OB2 association

Armstrong, Joseph J; Wright, Nicholas; Jeffries, Robin; Jackson, Richard J

Abstract

The kinematics of low-mass stars in nearby OB associations can provide clues about their origins and evolution. Combining the precise positions, proper motions, and parallaxes given in the second Gaia Data Release with radial-velocity measurements obtained with the Hermes spectrograph at the Anglo-Australian Telescope, we have an opportunity to study in detail the kinematics of low-mass stars belonging to the nearby ? Vel cluster and the Vela OB2 association it is projected against. The presence of lithium is used to confirm the youth of our targets. We separate our sample into the cluster and association populations based on the Gaia-ESO Survey membership probabilities their parallaxes, and kinematics. We find strong evidence for expansion in the OB association population with at least 4s significance along all three axes, though the expansion is notably anisotropic. We discuss these results in the context of cluster and association dispersal theories.

Citation

Armstrong, J. J., Wright, N., Jeffries, R., & Jackson, R. J. (2020). The dynamics of the γ Vel cluster and nearby Vela OB2 association. Monthly Notices of the Royal Astronomical Society, 494(4), 4794 -4801. https://doi.org/10.1093/mnras/staa939

• Journal Article Type: Article
• Acceptance Date: Mar 30, 2020
• Online Publication Date: Apr 8, 2020
• Publication Date: 2020-06
• Publicly Available Date: May 26, 2023
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 494
• Issue: 4
• Pages: 4794 -4801
• DOI: https://doi.org/10.1093/mnras/staa939
• Keywords: methods: data analysis, techniques: photometric, surveys, open clusters and associations: individual: Vela OB2, ? Velorum
• Publisher URL: https://doi.org/10.1093/mnras/staa939