Three-dimensional structure of the Upper Scorpius association with the Gaia first data release

Author(s)

Galli, Phillip A. B. ^[1] ; Joncour, Isabelle ^{[2, 3]} ; Moraux, Estelle ^[3]

Affiliation

^[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Rua Matao 1226, Cidade Univ, BR-05508900 Sao Paulo, SP - Brazil

^[2] Univ Maryland, Dept Astron, College Pk, MD 20742 - USA

^[3] Univ Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble - France

• Document type: Journal article
• Source: Monthly Notices of the Royal Astronomical Society; v. 477, n. 1, p. L50-L54, JUN 2018.
• Web of Science Citations: 6

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 x 38 x 32 pc(3), while the faintest cluster members define a more elongated structure with dimensions of 98 x 24 x 18 pc(3). We suggest that the different properties of both populations are an imprint of the star formation history in this region. (AU)

• FAPESP's process: 13/04934-8 - Kinematics and Evolution of Pre-Main Sequence Stars in Nearby Star-Forming Regions
• Grantee: Phillip Andreas Brenner Galli
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/14696-2 - Complementing Gaia from the ground with the dance survey in nearby star-forming regions
• Grantee: Phillip Andreas Brenner Galli
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor