J/MNRAS/515/687 Large-scale expansion of OB stars in Cygnus (Quintana+, 2022)
Large-scale expansion of OB stars in Cygnus.
Quintana A.L., Wright N.J.
<Mon. Not. R. Astron. Soc. 515, 687 (2022)>
=2022MNRAS.515..687Q 2022MNRAS.515..687Q (SIMBAD/NED BibCode)
ADC_Keywords: Associations, stellar ; Stars, OB ; Parallaxes, trigonometric ;
Proper motions ; Stars, ages ; Stars, distances ;
Stellar distribution
Keywords: stars: kinematics and dynamics - stars: early-type - stars: massive -
stars: distances -
open clusters and associations: individual: Biurakan 2, Dolidze 3,
FSR 0198, NGC 6871, NGC 6910, NGC 6913
Abstract:
The proper motions (PMs) of OB stars in Cygnus have recently been
found to exhibit two large-scale kinematic patterns suggestive of
expansion. We perform a 3D traceback on these OB stars, the newly
identified OB associations and related open clusters in the region. We
find that there are two groups of stars, associations and clusters and
that they were each more compact in the past, reaching their closest
approach 7.9+3.0-1.8 and 8.5+0.8-2.8Myr ago. We
consider two main scenarios for the driver of these large-scale
expansion patterns: feedback-driven expansion from a previous
generation of massive stars, and expansion as a result of the
turbulent velocity field in the primordial molecular cloud. While it
is tempting to attribute such large-scale expansion patterns to
feedback processes, we find that the observed kinematics are fully
consistent with the turbulent origin, and therefore that the injection
of further energy or momentum from feedback is not required. Similar
conclusions may be drawn for other star forming regions with
large-scale expansion patterns.
Description:
Position, proper motions and SED-fitted distance of the association
members.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
asscyg2.dat 83 664 Position, proper motions and SED-fitted distance
of the association members
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See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
J/ApJ/811/85 : RVs + V-band LCs of probable members of Cyg OB2 (Kiminki+, 2015)
Byte-by-byte Description of file: asscyg2.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaEDR3 Gaia EDR3 source identification number
(GaiaEDR3)
21- 30 F10.6 deg RAdeg Barycentric right ascension (ICRS) at
Ep=2016.0 of the source (ICRS) at Ep=2016.0
(RA_ICRS)
32- 40 F9.6 deg DEdeg Barycentric right ascension (ICRS) at
Ep=2016.0 of the source (ICRS) at Ep=2016.0
(DE_ICRS)
42- 47 F6.3 mas/yr pmGLON Proper motion in Galactic longitude direction
at Ep=2016.0 (pml)
49- 53 F5.3 mas/yr e_pmGLON Standard error of proper motion in Galactic
longitude direction (e_pml)
55- 60 F6.3 mas/yr pmGLAT Proper motion in Galactic latitude direction
at Ep=2016.0 (pmb)
62- 66 F5.3 mas/yr e_pmGLAT Standard error of proper motion in Galactic
latitude direction (e_pmb)
68- 71 I4 pc Dist Median SED-fitted distance (Dist)
73- 76 I4 pc b_Dist 16th percentile SED-fitted distance from the
posterior distribution (b_Dist)
78- 81 I4 pc B_Dist 84th percentile SED-fitted distance from the
posterior distribution (B_Dist)
83 A1 --- Assoc [ABCDEF] Association designation (Association)
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Acknowledgements:
Alexis Quintana, a.l.p.quintana(at)keele.ac.uk
(End) Patricia Vannier [CDS] 16-Aug-2022