The low mass population of the Vela OB2 association from Gaia

Armstrong, Joseph J; Jeffries, Robin D; Wright, Nicholas J

Abstract

The first Gaia Data Release presents an opportunity to characterise the low-mass population of OB associations, providing larger statistical samples and better constraints on the formation and evolution of clusters and associations. Using previously known low mass members in a small region of Vela OB2 we have designed selection criteria that combine Gaia and 2MASS photometry, independently of any astrometric information, to identify low-mass pre-main-sequence (PMS) stars over the wider association area. Our method picks out the known clusters of young stars around Velorum and NGC-2547, but also identifies other over-densities that may represent previously unknown clusters. There are clear differences in the spatial distributions of the low-mass and the high-mass OB populations, suggesting either that the structure and dynamics of these populations has evolved separately or that the initial mass function can vary considerably on small scales within a single association.

Citation

Armstrong, J. J., Jeffries, R. D., & Wright, N. J. (2018). The low mass population of the Vela OB2 association from Gaia. Monthly Notices of the Royal Astronomical Society: Letters, 480(1), L121–L125. https://doi.org/10.1093/mnrasl/sly137

• Journal Article Type: Article
• Acceptance Date: Jul 27, 2018
• Online Publication Date: Jul 27, 2018
• Publication Date: 2018-10
• Journal: Monthly Notices of the Royal Astronomical Society: Letters
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 480
• Issue: 1
• Article Number: sly137
• Pages: L121–L125
• DOI: https://doi.org/10.1093/mnrasl/sly137
• Keywords: surveys, Gaia, 2MASS, techniques, photometric, methods, data analysis, OB associations, Vela OB2
• Publisher URL: http://dx.doi.org/10.1093/mnrasl/sly137