The low-mass population of the Vela OB2 association from Gaia. (27th July 2018)

• Record Type: Journal Article
• Authors: Armstrong, Joseph J; Wright, Nicholas J; Jeffries, R D
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 480:Number 1(2018:Oct.)
• Page Start: L121
• Page End: L125
• Publication Date: 2018-07-27
• Subjects: Techniques: photometric -- Open clusters and associations: individual: Gamma Velorum, Vela OB2; Stars: pre-main-sequence; Astronomy -- Research -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnrasl/sly137
• Languages: English
• ISSNs: 1745-3933

Abstract

ABSTRACT: The first Gaia Data Release presents an opportunity to characterize 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 stars over the wider association area. Our method picks out the known clusters of young stars around γ 2 Velorum and NGC-2547, but also identifies other overdensities 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.