J/A+A/616/L15 Parallaxes and Proper Motions of OB stars (Xu+, 2018)
A comparison of local spiral structure from Gaia DR2 and VLBI maser parallaxes.
Xu Y., Bian S.B., Reid M.J., Li J.J., Zhang B., Yan Q.Z., Dame T.M.,
Menten K.M., He Z.H., Liao S.L., Tang Z.H.
<Astron. Astrophys. 616, L15 (2018)>
=2018A&A...616L..15X 2018A&A...616L..15X (SIMBAD/NED BibCode)
ADC_Keywords: Stars, OB ; Milky Way ; Parallaxes, trigonometric ; Proper motions
Keywords: Galaxy: structure - stars: earl- type - stars: massive - masers
Abstract:
The Gaia mission has released the second data set (Gaia DR2), which
contains parallaxes and proper motions for a large number of massive,
young stars.
We investigate the spiral structure in the solar neighborhood revealed
by Gaia DR2 and compare it with that depicted by VLBI maser
parallaxes.
We examined three samples with different constraints on parallax
uncertainty and distance errors and stellar spectral types: (1) all OB
stars with parallax errors less than 10%; (2) only O-type stars with
0.1mas errors imposed and with parallax distance errors less than
0.2kpc; (3) only O-type stars with 0.05 mas errors imposed and with
parallax distance errors less than 0.3kpc.
In spite of the significant distance uncertainties for stars in DR2
beyond 1.4kpc,the spiral structure in the solar neighborhood
demonstrated by Gaia agrees well with that illustrated by VLBI maser
results. The O-type stars available from DR2 extend the spiral arm
models determined from VLBI maser parallaxes into the fourth Galactic
quadrant, and suggest the existence of a new spur between the Local
and Sagittarius arms.
Description:
Parallaxes and Proper Motions of OB stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 172 5772 Parallaxes and proper motions of OB stars
table2.dat 172 284 Parallaxes and Proper Motions of O stars
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Source Name (Name)
11- 29 I19 --- Source Unique source identifier with Gaia DR2
(DR2sourceid)
31- 43 F13.9 deg RAdeg Right ascension (ICRS, epoch 2015.5) (ra)
45- 57 F13.9 deg DEdeg Declination (ICRS, epoch 2015.5) (dec)
59- 71 F13.9 mas plx ? Absolute stellar parallax (parallax)
73- 83 F11.9 mas e_plx ? Standard error of the stellar parallax
(parallax_error)
85- 98 F14.9 mas pmRA ? Proper motion in right ascension direction
(pmra)
100-110 F11.9 mas e_pmRA ? Standard error of pmra (pmra_error)
112-124 F13.9 mas pmDE ? Proper motion in declination direction
(pmdec)
126-136 F11.9 mas e_pmDE ? Standard error of pmdec (pmdec_error)
138-143 F6.1 km/s vlsr ? LSR velocity (vlsr)
145-149 F5.1 km/s e_vlsr ? Standard error of vlsr (velocity_error)
151-172 A22 --- SpType Spectral type (spectral_type)
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Acknowledgements:
Ye Xu, xuye(at)pmo.ac.cn
(End) Patricia Vannier [CDS] 26-Jun-2018