J/ApJ/883/8 Cand. young OB stars from GALEX & Gaia DR2 (Casetti-Dinescu+, 2019)
A kinematically cold structure of candidate young OB stars toward the
anticenter.
Casetti-Dinescu D.I., Girard T.M.
<Astrophys. J., 883, 8 (2019)>
=2019ApJ...883....8C 2019ApJ...883....8C
ADC_Keywords: Stars, OB; Photometry, ultraviolet; Optical; Surveys;
Parallaxes, trigonometric; Proper motions
Keywords: Galaxy structure; Galaxy kinematics; Milky Way disk ; star formation;
catalogs
Abstract:
We combine Galaxy Evolution Explorer and Gaia DR2 catalogs to track
star formation in the outskirts of our Galaxy. Using photometry,
proper motions, and parallaxes we identify a structure of ∼300 OB-type
candidates located between 12 and 15kpc from the Galactic center that
are kinematically cold. The structure is located between l=120°
and 200°, above the plane up to ∼700pc and below the plane to
∼1kpc. The bulk motion is disklike; however, we measure a mean upward
vertical motion of 5.7±0.4km/s, and a mean outward radial motion of
between 8 and 16km/s. The velocity dispersion along the least
dispersed of its proper-motion axes (perpendicular to the Galactic
disk) is 6.0±0.3km/s, confirming the young age of this structure.
While spatially encompassing the outer spiral arm of the Galaxy, this
structure is not a spiral arm. Its explanation as the Milky Way warp
is equally unsatisfactory. The structure's vertical extent, mean
kinematics, and asymmetry with respect to the plane indicate that its
origin is more akin to a wobble generated by a massive satellite
perturbing the Galaxy's disk. The mean stellar ages in this outer
structure indicate the event took place some 200Myr ago.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 148 396 List of OB candidates
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See also:
VII/242 : LEDA galaxies with DENIS measurements catalog (Paturel+, 2005)
VI/137 : GaiaSimu Universe Model Snapshot (Robin+, 2012)
II/335 : Revised cat. of GALEX UV sources (GUVcat_AIS GR6+7) (Bianchi+ 2017)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/543/A100 : GaiaSimu Universe Model Snapshot (Robin+, 2012)
J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)
J/MNRAS/441/715 : MIR study of RR Lyrae stars (Gavrilchenko+, 2014)
J/ApJ/783/130 : Plx of high mass star forming regions (Reid+, 2014)
J/MNRAS/448/2260 : WD candidates in SDSS DR10 (Gentile Fusillo+, 2015)
J/ApJS/221/12 : AGNs in the MIR using AllWISE data (Secrest+, 2015)
J/ApJS/224/7 : CO obs. of the outer arm in the 2nd quadrant (Du+, 2016)
J/ApJS/224/4 : GOSSS III. O-type systems (Maiz Apellaniz+, 2016)
J/A+A/614/A140 : Large Quasar Astrometric Catalogue 4 (Gattano+, 2018)
J/A+A/618/A93 : Gaia DR2 open clusters in the MW (Cantat-Gaudin+, 2018)
J/A+A/616/A10 : Open clusters GaiaDR2 HR diag. (Gaia Collaboration, 2018)
J/A+A/616/L15 : Parallaxes and Proper Motions of OB stars (Xu+, 2018)
J/A+A/621/A38 : Gaia catalogue of hot subluminous stars (Geier+, 2019)
J/A+A/622/A60 : Gaia DR2 misclassified RR Lyrae list (Clementini+, 2019)
J/MNRAS/485/2312 : Outer Galactic disk A & F star motions (Harris+, 2019)
J/ApJS/241/32 : OB stars from the LAMOST DR5 spectra (Liu+, 2019)
J/A+A/642/A21 : Astrometric parameters for 135 OB stars (Russeil+, 2020)
J/A+A/645/L8 : Plx & PMs of OB stars from Gaia EDR3 (Xu+, 2021)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- Gaia Gaia DR2 object identifier
21- 39 I19 --- GALEX GALEX object identifier
41- 48 F8.4 deg GLON [121.7/201] Galactic longitude
50- 57 F8.4 deg GLAT [-15/14.7] Galactic latitude
59- 64 F6.3 mas Plx [-0.11/0.25] Gaia DR2 Parallax
66- 71 F6.3 mas/yr pmGLON [-2/1.5] Proper motion, Galactic longitude
73- 78 F6.3 mas/yr pmGLAT [-0.8/0.8] Proper motion, Galactic latitude
80- 84 F5.3 mas e_Plx [0.018/0.1] Uncertainty in Plx
86- 90 F5.3 mas/yr e_pmGLON [0.02/0.2] Uncertainty in pmGLON
92- 96 F5.3 mas/yr e_pmGLAT [0.02/0.2] Uncertainty in pmGLAT
98-103 F6.3 mag GB0 [11.34/15.51] Reddening corrected,
Gaia BP magnitude
105-110 F6.3 mag GR0 [12/15.7] Reddening corrected,
Gaia RP magnitude
112-117 F6.3 mag FUV0 [9.17/16.75] Reddening corrected,
GALEX FUV magnitude
119-124 F6.3 mag NUV0 [8.94/16.7] Reddening corrected,
GALEX NUV magnitude
126-130 F5.3 mag e_FUV0 [0.007/0.2] Uncertainty in GALEX FUV0
132-136 F5.3 mag e_NUV0 [0.005/0.1] Uncertainty in GALEX NUV0
138-142 F5.3 arcsec Sep [0.02/2.9] Separation
144-148 F5.3 mag E(B-V) [0.06/1.3] Reddening,
Schlegel+ (1998ApJ...500..525S 1998ApJ...500..525S)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 22-Feb-2021