J/ApJ/859/33 GOBELINS. IV. VLBA obs. of Taurus (Galli+, 2018)
The Gould's Belt Distances Survey (GOBELINS).
IV. Distance, depth, and kinematics of the Taurus star-forming region.
Galli P.A.B., Loinard L., Ortiz-Leon G.N., Kounkel M., Dzib S.A.,
Mioduszewski A.J., Rodriguez L.F., Hartmann L., Teixeira R., Torres R.M.,
Rivera J.L., Boden A.F., Evans II N.J., Briceno C., Tobin J.J., Heyer M.
<Astrophys. J., 859, 33 (2018)>
=2018ApJ...859...33G 2018ApJ...859...33G
ADC_Keywords: Star Forming Region; Radio sources; Proper motions;
Parallaxes, trigonometric; Stars, distances; YSOs;
Molecular clouds
Keywords: astrometry ; binaries: visual ; radiation mechanisms: non-thermal ;
stars: distances ; stars: kinematics and dynamics ;
techniques: interferometric
Abstract:
We present new trigonometric parallaxes and proper motions of young
stellar objects in the Taurus molecular cloud complex from
observations collected with the Very Long Baseline Array as part of
the Gould's Belt Distances Survey. We detected 26 young stellar
objects and derived trigonometric parallaxes for 18 stars with an
accuracy of 0.3% to a few percent. We modeled the orbits of six
binaries and determined the dynamical masses of the individual
components in four of these systems (V1023 Tau, T Tau S, V807 Tau, and
V1000 Tau). Our results are consistent with the first trigonometric
parallaxes delivered by the Gaia satellite and reveal the existence of
significant depth effects. We find that the central portion of the
dark cloud Lynds 1495 is located at d=129.5±0.3pc, while the B216
clump in the filamentary structure connected to it is at
d=158.1±1.2pc. The closest and remotest stars in our sample are
located at d=126.6±1.7pc and d=162.7±0.8pc, yielding a distance
difference of about 36pc. We also provide a new distance estimate for
HL Tau that was recently imaged. Finally, we compute the spatial
velocity of the stars with published radial velocity and investigate
the kinematic properties of the various clouds and gas structures in
this region.
Description:
The observations presented in this paper were obtained with the Very
Long Baseline Array (VLBA) near the equinoxes of every year between
2012 August and 2017 October. The data were recorded in dual
polarization mode with a bandwidth of 256MHz centered at ν=5.0 or
8.4GHz (C and X bands, respectively). We observed with the X band
during the first 3yr of our observing program and then switched to
the C band.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 92 307 Observed fields in Taurus with the VLBA
table2.dat 109 91 VLBA detections and nondetections in Taurus
table3.dat 77 70 VLBA data in Taurus from the NRAO archive
table4.dat 106 311 VLBA measured positions for the sources in our sample
table5.dat 106 18 Proper motions, parallaxes, and distances derived
from VLBA observations
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2014)
VII/7 : Lynds' Catalogue of Dark Nebulae (LDN) (Lynds 1962)
VII/244 : Atlas and Catalog of Dark Clouds (Dobashi+, 2005)
J/ApJ/578/914 : Low-mass stars in Taurus (Hartmann, 2002)
J/AN/328/889 : Mean Radial Velocities of open clusters (Kharchenko+, 2007)
J/ApJS/186/259 : Taurus Spitzer survey: new candidate members (Rebull+, 2010)
J/ApJ/724/835 : The Spitzer c2d survey of WTTSs. III. (Wahhaj+, 2010)
J/ApJ/723/1542 : Optical high-resolution spectroscopy of WTTSs (Xing, 2010)
J/ApJ/751/115 : Millimeter emission from Taurus bin. systems (Harris+, 2012)
J/ApJ/745/119 : Close companions to young stars I. ChaI & Tau (Nguyen+, 2012)
J/ApJ/801/91 : Gould's Belt Very Large Array survey IV. Taurus (Dzib+, 2015)
J/MNRAS/472/675 : Wide binaries in Tycho-Gaia: search method (Andrews+, 2017)
J/A+A/599/A14 : Taurus ultra-wide pairs (Joncour+, 2017)
J/ApJ/834/142 : GOBELINS. II. OMC (Kounkel+, 2017)
J/ApJ/838/150 : The Taurus-Auriga ecosystem. I. (Kraus+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Code NRAO project code
9- 19 A11 "D/M/Y" Date Observation date (UT)
21- 21 A1 --- Band Observed band (X=8.4GHz, 216 occurrences or
C=5.0GHz, 91 occurrences)
23- 24 I2 h RAh [4/4] Hour of Right Ascension (J2000) (1)
26- 27 I2 min RAm [13/56] Minute of Right Ascension (J2000) (1)
29- 33 F5.2 s RAs [2.2/58.97] Second of Right Ascension (J2000) (1)
35 A1 --- DE- [+] Sign of Declination (J2000) (1)
36- 37 I2 deg DEd [18/30] Degree of Declination (J2000) (1)
39- 40 I2 arcmin DEm [1/59] Arcminute of Declination (J2000) (1)
42- 45 F4.1 arcsec DEs [0.3/59.5] Arcsecond Declination (J2000) (1)
47- 92 A46 --- Calib Calibrators (2)
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Note (1): Of the field center.
Note (2): The main calibrator is the first source in the list.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- GBS-VLA GBS-VLA identifier (JHHMMSS.ss+DDMMSS.s) (1)
21- 44 A24 --- OName Other identifier
46 A1 --- l_F5GHzmin Limit flag on F5GHzmin
48- 52 F5.2 mJy F5GHzmin [0.05/11.2]? Minimum flux at 5.0GHz
54- 57 F4.2 mJy e_F5GHzmin [0.04/0.09]? F5GHzmin uncertainty
59- 63 F5.2 mJy F5GHzmax [0.1/12]? Maximum flux at 5.0GHz
65- 68 F4.2 mJy e_F5GHzmax [0.04/0.07]? F5GHzmax uncertainty
70 A1 --- l_F8.4Ghzmin Limit flag on F8.4GHzmin
72- 76 F5.2 mJy F8.4Ghzmin [0.09/20.4]? Minimum flux at 8.4GHz
78- 81 F4.2 mJy e_F8.4Ghzmin [0.05/0.4]? F8.4Ghzmin uncertainty
83- 87 F5.2 mJy F8.4Ghzmax [0.1/69]? Maximum flux at 8.4GHz
89- 92 F4.2 mJy e_F8.4Ghzmax [0.06/0.7]? F8.4Ghzmax uncertainty
94- 97 F4.2 --- logTB [6.1/9.1]? log of brightness temperature
99-103 A5 --- Type Type of source (2)
105-106 I2 --- Nd [0/14] Number of detections
108-109 I2 --- No [3/14] Number of observations
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Note (1): The GBS-VLA (Gould's Belt Very Large Array Survey) identifier is
defined by Dzib+ (2015, J/ApJ/801/91).
Note (2): Type of source as follows:
YSO = Young Stellar Object (40 occurrences);
Star? = field star (3 sources);
B = background source (Galactic or extragalactic -- 23 occurrences).
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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- 7 A7 --- Code NRAO project code
9- 19 A11 "Y/M/D" Date Observation date (UT)
21- 30 A10 --- Name Source identifier
32- 77 A46 --- Calib Calibrators (1)
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Note (1): The main calibrator is the first source in the list.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 27 A27 --- Source Source identifier
29- 35 A7 --- Code NRAO project code
37- 49 F13.5 d JD [2452906.9/2458041] Julian Day of
the observation
51- 52 I2 h RAh [4] Hour of Right Ascension (J2000)
54- 55 I2 min RAm [13/56] Minute of Right Ascension (J2000)
57- 67 F11.8 s RAs Second of Right Ascension (J2000)
69 A1 --- DE- [+] Sign of Declination (J2000)
70- 71 I2 deg DEd [18/30] Degree of Declination (J2000)
73- 74 I2 arcmin DEm Arcminute of Declination (J2000)
76- 85 F10.7 arcsec DEs Arcsecond Declination (J2000)
87- 96 F10.8 s e_RAs [8e-8/2.1e-5] Uncertainty in RAs
98-106 F9.7 arcsec e_DEs [2e-6/0.0005] Uncertainty in DEs
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Source identifier
25- 31 F7.3 mas/yr pmRA [-52.8/11.3] Proper motion along RA,
µαcosδ
33- 38 F6.4 mas/yr e_pmRA [0.01/2.2] pmRA uncertainty
40- 46 F7.3 mas/yr pmDE [-28.8/-11.1] Proper motion along DEC,
µδ
48- 52 F5.3 mas/yr e_pmDE [0.01/2.2] pmDE uncertainty
54- 59 F6.3 mas/yr2 alphaRA ? Acceleration ααcosδ
61- 65 F5.3 mas/yr2 e_alphaRA ? alphaRA uncertainty
67- 71 F5.3 mas/yr2 alphaDE ? Acceleration αδ
73- 77 F5.3 mas/yr2 e_alphaDE ? alphaDE uncertainty
79- 84 F6.3 mas Plx [6.1/11.9] Trigonometric parallax
86- 90 F5.3 mas e_Plx [0.02/1.4] Plx uncertainty
92- 96 F5.1 pc Dist [84/163] Distance
98-101 F4.1 pc e_Dist [0.5/18.2] Negative error on Dist
103-106 F4.1 pc E_Dist [0.5/25.5] Positive error on Dist
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History:
From electronic version of the journal
References:
Ortiz-Leon et al. Paper I. 2017ApJ...834..141O 2017ApJ...834..141O
Ortiz-Leon et al. Paper II. 2017ApJ...834..142O 2017ApJ...834..142O Cat. J/ApJ/834/142
Ortiz-Leon et al. Paper III. 2017ApJ...834..143O 2017ApJ...834..143O
Galli et al. Paper IV. 2018ApJ...859...33G 2018ApJ...859...33G This catalog
Ortiz-Leon et al. Paper V. 2018ApJ...865...73O 2018ApJ...865...73O Cat. J/ApJ/865/73
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 04-Apr-2019