文章基本信息

标题：A ring in a shell: the large-scale 6D structure of the Vela OB2 complex ⋆ ⋆⋆
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作者：T. Cantat-Gaudin ; M. Mapelli ; L. Balaguer-Núñez 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2019
卷号：621
DOI：10.1051/0004-6361/201834003
语种：English
出版社：EDP Sciences
摘要：Context. The Vela OB2 association is a group of ∼10 Myr stars exhibiting a complex spatial and kinematic substructure. The all-skyGaiaDR2 catalogue contains proper motions, parallaxes (a proxy for distance), and photometry that allow us to separate the various components of Vela OB2.Aims. We characterise the distribution of the Vela OB2 stars on a large spatial scale, and study its internal kinematics and dynamic history.Methods. We make use ofGaiaDR2 astrometry and publishedGaia-ESO Survey data. We apply an unsupervised classification algorithm to determine groups of stars with common proper motions and parallaxes.Results. We find that the association is made up of a number of small groups, with a total current mass over 2330M⊙. The three-dimensional distribution of these young stars trace the edge of the gas and dust structure known as the IRAS Vela Shell across ∼180 pc and shows clear signs of expansion.Conclusions. We propose a common history for Vela OB2 and the IRAS Vela Shell. The event that caused the expansion of the shell happened before the Vela OB2 stars formed, imprinted the expansion in the gas the stars formed from, and most likely triggered star formation.
关键词：enstars: pre-main sequenceISM: individual objects: IRAS Vela ShellISM: individual objects: Gum NebulaISM: bubblesopen clusters and associations: individual: Vela OB2