Three-dimensional structure of the Upper Scorpius association with the Gaia first data release. (8th March 2018)

• Record Type: Journal Article
• Authors: Galli, Phillip A B; Joncour, Isabelle; Moraux, Estelle
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 477:Number 1(2018:Jun.)
• Page Start: L50
• Page End: L54
• Publication Date: 2018-03-08
• Subjects: methods: statistical -- proper motions -- stars: distances -- Galaxy: kinematics and dynamics -- open clusters and associations: individual: Upper Scorpius; Astronomy -- Research -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnrasl/sly036
• Languages: English
• ISSNs: 1745-3933

Abstract

Abstract: Using new proper motion data from recently published catalogues, we revisit the membership of previously identified members of the Upper Scorpius association. We confirmed 750 of them as cluster members based on the convergent point method, compute their kinematic parallaxes, and combined them with Gaia parallaxes to investigate the 3D structure and geometry of the association using a robust covariance method. We find a mean distance of 146 ± 3 ± 6 pc and show that the morphology of the association defined by the brightest (and most massive) stars yields a prolate ellipsoid with dimensions of 74 × 38 × 32 pc 3, while the faintest cluster members define a more elongated structure with dimensions of 98 × 24 × 18 pc 3 . We suggest that the different properties of both populations are an imprint of the star formation history in this region.