J/MNRAS/487/2771 Gaia-DR2 distance to the W3 Complex (Navarete+, 2019)
Gaia-DR2 distance to the W3 Complex in the Perseus Arm.
Navarete F., Galli P.A.B., Damineli A.
<Mon. Not. R. Astron. Soc. 487, 2771 (2019)>
=2019MNRAS.487.2771N 2019MNRAS.487.2771N (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Stars, distances ; Stars, early-type ;
Infrared sources
Keywords: stars: distances - stars: early type - stars: fundamental parameters -
HII regions - Galaxy: structure
Abstract:
The Perseus Arm is the closest Galactic spiral arm from the Sun,
offering an excellent opportunity to study in detail its stellar
population. However, its distance has been controversial with
discrepancies by a factor of two. Kinematic distances are in the range
3.9-4.2kpc as compared to 1.9-2.3kpc from spectrophotometric and
trigonometric parallaxes, reinforcing previous claims that this arm
exhibits peculiar velocities. We used the astrometric information of a
sample of 31 OB stars from the star-forming W3Complex to identify
another 37 W3 members and to derive its distance from their Gaia-DR2
parallaxes with improved accuracy. The Gaia-DR2 distance to the
W3Complex, 2.14+0.08-0.07kpc, coincides with the previous
stellar distances of ∼2kpc. The Gaia-DR2 parallaxes tentatively show
differential distances for different parts of the W3 Complex: W3 Main,
located to the NE direction, is at 2.30+0.19-0.16kpc, the W3
Cluster (IC1795), in the central region of the complex, is at
2.17+0.12-0.11kpc, and W3(OH) is at 2.00+0.29-0.23kpc to
the SW direction. The W3 Cluster is the oldest region, indicating that
it triggered the formation of the other two star-forming regions
located at the edges of an expanding shell around the cluster.
Description:
A total of 48 OB stars within the W3 Complex, centred at RA=02:26:32.4,
DE=+62:00:27 and covering a ∼20'x20' region, were investigated and
classified by Navarete et al. (2011AJ....142...67N 2011AJ....142...67N), Bik et al.
(2012ApJ...744...87B 2012ApJ...744...87B) and Kiminki et al. (2015, Cat. J/ApJ/813/42) and
their properties are listed in Table 2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 114 48 Known OB stars associated with the W3 Complex
table3.dat 116 36 Gaia-DR2 astrometric information of the OB-type
stellar population of the W3 Complex
table4.dat 121 37 Gaia-DR2 data of the new W3 members selected
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJ/813/42 : O and B type stars in W3: first results (Kiminki+, 2015)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- ID [1/48] ID of the source
4- 20 A17 --- Name Name of the source
22- 23 I2 h RAh Right ascension (J2000)
25- 26 I2 min RAm Right ascension (J2000)
28- 31 F4.1 s RAs Right ascension (J2000)
33 A1 --- DE- Declination sign (J2000)
34- 35 I2 deg DEd Declination (J2000)
37- 38 I2 arcmin DEm Declination (J2000)
40- 43 F4.1 arcsec DEs Declination (J2000)
45- 54 A10 --- SpType MK Spectral type
55- 64 A10 --- W3sub Associated subregion of the W3 Complex
66- 68 A3 --- Ref Reference (1)
70- 85 A16 --- 2MASS 2MASS designation
87- 90 F4.2 arcsec off2M ? Offset between the source and 2MASS
coordinates
92-114 A23 --- SName Simbad name
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Note (1): References as follows:
B12 = Bik et al., 2012ApJ...744...87B 2012ApJ...744...87B
K15 = Kiminki et al., 2015, Cat. J/ApJ/813/42
N11 = Navarete et al., 2011AJ....142...67N 2011AJ....142...67N
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- ID [1/48] ID of the source (same as table 2)
4- 21 A18 --- GDR2 Gaia DR2 designation
23- 26 F4.2 arcsec off2M Offset between 2MASS and Gaia-DR2 coordinates
28- 36 F9.6 deg RAdeg Right ascension (ICRS) at epoch 2015.5 of
the Gaia-DR2 source
38- 46 F9.6 deg DEdeg Declination (ICRS) at epoch 2015.5 of
the Gaia-DR2 source
48- 53 F6.3 mas/yr pmRA Proper motion in the RA axis, pmRA*cosDE
55- 60 F6.3 mas/yr e_pmRA Error on the proper motion in the RA axis
62- 67 F6.3 mas/yr pmDE Proper motion in the DE axis
69- 74 F6.3 mas/yr e_pmDE Error on the proper motion in the DE axis
76- 79 F4.2 mas/yr pmTot Total proper motion
81- 84 F4.2 mas/yr e_pmTot Error on the total proper motion
86- 91 F6.3 mas Plx Gaia-DR2 absolute parallax
93- 98 F6.3 mas e_Plx Error on the Gaia-DR2 parallax
100-104 F5.2 mag Gmag Gaia G-band magnitude
106-109 F4.2 mag BP-RP Gaia BP-RP colour index
111-114 F4.2 --- RUWE Re-Normalised Unit Weight Error
116 A1 --- flag [*] sources with an * have RUWE>1.4 and are
excluded from the analysis
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- ID ID of the source (GNN)
5- 22 A18 --- GDR2 Gaia DR2 designation
24- 33 A10 --- W3sub Associated subregion of the W3 Complex
35- 43 F9.6 deg RAdeg Right ascension (J2000) of the Gaia-DR2 source
45- 53 F9.6 deg DEdeg Declination (J2000) of the Gaia-DR2 source
55- 60 F6.3 mas/yr pmRA Proper motion in the RA axis, pmRA*cosDE
62- 67 F6.3 mas/yr e_pmRA Error on the proper motion in the RA axis
69- 74 F6.3 mas/yr pmDE Proper motion in the Dec axis
76- 81 F6.3 mas/yr e_pmDE Error on the proper motion in the Dec axis
83- 86 F4.2 mas/yr pmTot Total proper motion
88- 91 F4.2 mas/yr e_pmTot Error on the total proper motion
93- 98 F6.3 mas Plx Gaia-DR2 absolute parallax
100-105 F6.3 mas e_Plx Error on the Gaia-DR2 parallax
107-111 F5.2 mag Gmag Gaia-DR2 G-band magnitude
113-116 F4.2 mag BP-RP Gaia-DR2 BP-RP colour index
118-121 F4.2 --- RUWE Gaia-DR2 Re-Normalised Unit Weight Error
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Acknowledgements:
Felipe Navarete, navarete(at)gmail.com
(End) Patricia Vannier [CDS] 31-May-2019