J/MNRAS/517/5704 Catalogue of members of Vela OB2 (Armstrong+, 2022)
The Structure and 3D Kinematics of Vela OB2.
Armstrong J.J., Wright N.J., Jeffries R.D., Jackson R.J., Cantat-Gaudin T.
<Mon. Not. R. Astron. Soc. 517, 5704-5720 (2022)>
=2022MNRAS.517.5704A 2022MNRAS.517.5704A (SIMBAD/NED BibCode)
ADC_Keywords: Associations, stellar ; Clusters, open ; Spectroscopy ;
Stars, pre-main sequence ; Proper motions ; Optical ;
Parallaxes, trigonometric
Keywords: techniques: spectroscopic - surveys - stars: kinematics and dynamics -
stars: pre-main-sequence - open clusters and associations:
individual: Vela OB2, NGC 2547, gamma Vel, P Puppis
Abstract:
The kinematics of stars in OB associations can provide insights into
their formation, dynamical evolution, and eventual fate. The low-mass
stellar content of OB associations are sufficiently numerous as to
provide a detailed sampling of their kinematic properties, however
spectroscopy is required to confirm the youth of individual stars and
to get 3D kinematics. In this paper we present and analyse results
from a large spectroscopic survey of Vela OB2 conducted using
2dF/HERMES on the AAT. This spectroscopy is used to confirm the youth
of candidate young stars and determine radial velocities, which are
combined with proper motions and parallaxes from Gaia to measure
3-dimensional positions and velocities. We identify multiple separate
kinematic groups in the region, for which we measure velocity
dispersions and infer their virial states. We measure expansion rates
for all these groups and find strong evidence for anisotropic
expansion in the Vela OB2 association of at least 11 sigma
significance in all three dimensions, as well as some evidence for
expansion in the gamma Vel and P Puppis clusters. We trace back the
motions of these groups into the past and find that the open cluster
NGC 2547 is an interloper in the Vela OB2 region and actually formed
>100pc away from the association. We conclude that Vela OB2 must have
formed with considerable spatial and kinematic substructure over a
timescale of ∼10Myr, with clear temporal substructure within the
association, but no clear evidence for an age gradient.
Description:
Spectroscopic parameters for 2635 candidate pre-main sequence stars in
the Vela OB2 region. For each source confirmed to be pre-main sequence
by our spectroscopic criteria and with sufficient SNR to obtain
precise radial velocities, we combine spectroscopic radial velocities
with Gaia Early Data Release 3 (Gaia EDR3) 5-parameter astrometry to
calculate 6D Cartesian positions and velocities.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 94 2635 Spectroscopic parameters for observed sources
table2.dat 313 410 Astrometric parameters for identified PMS stars
with Gaia EDR3 ruwe < 1.4
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See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 F15.11 deg RAdeg Barycentric right ascension of the source
(ICRS) at Ep=2016.0
17- 31 F15.11 deg DEdeg Barycentric declination of the source
(ICRS) at Ep=2016.0
33- 37 F5.2 --- SNR ? Signal-to-noise ratio
39- 46 F8.2 0.1pm EW(Li) ? Equivalent-width of Li 6708Å
48- 53 F6.2 0.1pm e_EW(Li) ? Equivalent-width of Li error
55- 62 F8.3 --- Hac ? H-alpha(core) index
64- 70 F7.3 --- Haw ? H-alpha(wings) index
72- 79 F8.3 0.1pm EW(Ha) ? Equivalent-width of H-alpha 6563A
81- 87 F7.2 km/s RV ? Spectroscopic radial velocity
89- 94 F6.2 km/s e_RV ? Spectroscopic radial velocity error
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaEDR3 Gaia EDR3 source identifier (Cat. I/350)
21- 35 F15.11 deg RAdeg Barycentric right ascension of the source
(ICRS) at Ep=2016.0
37- 42 F6.4 mas e_RAdeg Standard error eRA=eRA*cosDE of the right
ascension of the source in ICRS at Ep=2016.0
44- 58 F15.11 deg DEdeg Barycentric declination of the source
(ICRS) at Ep=2016.0
60- 65 F6.4 mas e_DEdeg Standard error of the declination of the
source in ICRS at at Ep=2016.0
67- 72 F6.4 mas Plx Absolute stellar parallax of the source at
the Ep=2016.0
74- 79 F6.4 mas e_Plx Standard error of the stellar parallax at
Ep=2016.0
81- 87 F7.3 mas/yr pmRA Proper motion in right ascension pmRA*cosDE
of the source in ICRS at Ep=2016.0
89- 93 F5.3 mas/yr e_pmRA Standard error of proper motion in
right ascension direction
95-100 F6.3 mas/yr pmDE Proper motion in declination direction
102-106 F5.3 mas/yr e_pmDE Standard error of proper motion in
declination direction
108-112 F5.3 --- RUWE Renormalised unit weight error
114-120 F7.4 mag Gmag G-band mean magnitude (Vega)
122-128 F7.4 mag BPmag Integrated BP mean magnitude (Vega)
130-136 F7.4 mag RPmag Integrated RP mean magnitude (Vega)
138-151 F14.10 deg GLON Galactic longitude (l)
153-166 F14.10 deg GLAT Galactic latitude (b)
168-174 F7.2 km/s RV Spectroscopic radial velocity
176-181 F6.2 km/s e_RV Spectroscopic radial velocity error
183-189 F7.3 pc X Galactic Cartesian position in X (1)
191-195 F5.3 pc E_X Positive error of Galactic Cartesian position
in X (1)
197-201 F5.3 pc e_X Negative error of Galactic Cartesian position
in X (1)
203-210 F8.3 pc Y Galactic Cartesian position in Y (1)
212-217 F6.3 pc E_Y Positive error of Galactic Cartesian position
in Y (1)
219-224 F6.3 pc e_Y Negative error of Galactic Cartesian position
in Y (1)
226-232 F7.3 pc Z Galactic Cartesian position in Z (1)
234-238 F5.3 pc E_Z Positive error of Galactic Cartesian position
in Z (1)
240-244 F5.3 pc e_Z Negative error of Galactic Cartesian position
in Z (1)
246-252 F7.3 km/s U Galactic Cartesian velocity in X (1)
254-259 F6.3 km/s E_U Positive error of Galactic Cartesian velocity
in X (1)
261-266 F6.3 km/s e_U Negative error of Galactic Cartesian velocity
in X (1)
268-275 F8.3 km/s V Galactic Cartesian velocity in Y (1)
277-283 F7.3 km/s E_V Positive error of Galactic Cartesian velocity
in Y (1)
285-291 F7.3 km/s e_V Negative error of Galactic Cartesian velocity
in Y (1)
293-299 F7.3 km/s W Galactic Cartesian velocity in Z (1)
301-306 F6.3 km/s E_W Positive error of Galactic Cartesian velocity
in Z (1)
308-313 F6.3 km/s e_W Negative error of Galactic Cartesian velocity
in Z (1)
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Note (1): The Galactic Cartesian coordinate system has it's origin at the
position of the Sun with the positive X direction towards the Galactic center,
the positive Y direction in the direction of Galactic rotation and the
positive Z direction perpendicular to the Galactic plane in the direction of
positive Galactic latitude.
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Acknowledgements:
Joseph J. Armstrong, joseph.armstrong(at)chalmers.se
(End) Joseph Armstrong [Chalmers, Sweden], Patricia Vannier [CDS] 12-Oct-2022