A ring in a shell: the large-scale 6D structure of the Vela OB2 complex
Journal
Date Issued
2019
Author(s)
Cantat-Gaudin, T.
•
Mapelli, M.
•
Balaguer-Núñez, L.
•
Jordi, C.
•
•
Abstract
Context. The Vela OB2 association is a group of ∼10 Myr stars exhibiting a complex spatial and kinematic substructure. The all-sky Gaia DR2 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 of Gaia DR2 astrometry and published Gaia-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 2330 M☉. 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.
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 of Gaia DR2 astrometry and published Gaia-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 2330 M☉. 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.
The movie associated to Fig. 6 is available at http://https://www.aanda.orgSelected young stars from photometry and their membership probability are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/621/A115
Volume
621
Start page
A115
Issn Identifier
0004-6361
Ads BibCode
2019A&A...621A.115C
Rights
open.access
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