J/A+A/645/L8 Parallaxes & proper motions of OB stars from Gaia EDR3 (Xu+, 2021)
Local spiral structure based on the Gaia EDR3 parallaxes.
Xu Y., Hou L.H., Bian S.B., Hao C.J., Liu D.J., Li J.J., Li Y.J.
<Astron. Astrophys. 645, L8 (2021)>
=2021A&A...645L...8X 2021A&A...645L...8X (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Stars, OB ; Parallaxes, trigonometric ;
Proper motions
Keywords: astrometry - Galaxy: structure - stars: early type -
stars: massive - masers
Abstract:
The astrometric satellite Gaia is expected to significantly increase
our knowledge as to the properties of the MilkyWay. The Gaia Early
Data Release 3 (Gaia EDR3) provides the most precise parallaxes for
many OB stars, which can be used to delineate the Galactic spiral
structure.
We investigate the local spiral structure with the largest sample of
spectroscopically confirmed young OB stars available to date, and we
compare it with what was traced by the parallax measurements of
masers.
A sample consisting of three different groups of massive young stars,
including O-B2 stars, O-B0 stars and O-type stars with parallax
accuracies better than 10% was compiled and used in our analysis.
The local spiral structures in all four Galactic quadrants within
∼5kpc of the Sun are clearly delineated in detail. The revealed
Galactic spiral pattern outlines a clear sketch of nearby spiral arms,
especially in the third and fourth quadrants where the maser parallax
data are still absent. These O-type stars densify and extend the
spiral structure constructed by using the Very Long Baseline
Interferometry (VLBI) maser data alone. The clumped distribution of
O-type stars also indicates that the Galaxy spiral structure is
inhomogeneous.
Description:
Parallaxes and proper motions of OB stars from Gaia EDR3.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 126 9750 Parallaxes and proper motions of OB stars
from Gaia EDR3
--------------------------------------------------------------------------------
See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 26 A26 --- Name Source Name (name_skiff)
28- 46 I19 --- GaiaEDR3 Unique source identifier with Gaia EDR3
(EDR3sourceid)
48- 55 F8.4 deg RAdeg Right ascension (ICRS, epoch 2016) (ra)
57- 64 F8.4 deg DEdeg Declination (ICRS, epoch 2016) (dec)
66- 71 F6.3 mas Plx ? Absolute stellar parallax (parallax)
73- 77 F5.3 mas e_Plx ? Standard error of the stellar parallax
(parallax_error)
79- 84 F6.2 mas/yr pmRA ? Proper motion in right ascension direction,
pmRA*cosDE (pmra)
86- 89 F4.2 mas/yr e_pmRA ? Standard error of pmra (pmra_error)
91- 96 F6.2 mas/yr pmDE ? Proper motion in declination direction
(pmdec)
98-101 F4.2 mas/yr e_pmDE ? Standard error of pmdec (pmdec_error)
103-126 A24 --- SpType Spectral type (spectral_type)
--------------------------------------------------------------------------------
Acknowledgements:
Ye Xu, xuye(at)pmo.ac.cn
(End) Patricia Vannier [CDS] 04-Jan-2021