J/ApJ/869/122 SDSS-DR14 and LAMOST DR6 spectra in GD-1 stream (Li+, 2018)
GD-1: the relic of an old metal-poor globular cluster.
Li G.-W., Yanny B., Wu Y.
<Astrophys. J., 869, 122 (2018)>
=2018ApJ...869..122L 2018ApJ...869..122L
ADC_Keywords: Spectra, optical; Proper motions; Photometry, SDSS;
Abundances, [Fe/H]; Radial velocities; Stars, blue
Keywords: Galaxy: abundances; Galaxy: kinematics and dynamics;
Galaxy: structure; globular clusters: general
Abstract:
Combining data from Gaia DR2, SDSS DR14, and LAMOST DR6, we update the
fit to model of the properties of the stellar stream GD-1 and find
that it has an age of ∼13Gyr, [Fe/H] of -2.2±0.12, and a distance
from the Sun of ∼8kpc. We tabulate six-dimensional (6D) phase-space
fiducial points along the GD-1 stream orbit over a 90° arc. The
fitted orbit shows that the stream has an eccentricity e∼0.3,
perigalacticon of 14.2kpc, apogalacticon of 27.0kpc, and inclination
i∼40°. There is evidence along the arc for four candidate stellar
overdensities, one candidate gap, two candidate stellar
underdensities, and that the stream is cut off at φ1∼2° (in
the stream-aligned (φ1, φ2) coordinate system of Koposov+
2010ApJ...712..260K 2010ApJ...712..260K). The spur originating at φ1~-40°
implies stars were pulled away from the stream trace by an encounter
(potentially a dark matter subhalo). The narrowest place (FWHM∼44.6pc)
of the GD-1 trace is at (φ1, φ2c)~(-14°, 0.15°),
which is ~(178.18°, 52.19°) in (RA, DE), where the progenitor
is possibly located. We also find six blue horizontal branch and 10
blue stragglers spectroscopic stars in the GD-1 stream.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 106 136 SDSS DR14 spectra
table4.dat 121 32 LAMOST DR6 spectra
table6.dat 88 15 Spectra of blue horizontal branch (BHB) and
BS (blue straggler) stars in LAMOST DR6
table7.dat 83 11 Spectra of BHB and BS stars in SDSS DR14
table8.dat 79 28 BHB and BS stars of the GD-1 stream
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See also:
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
V/164 : LAMOST DR5 catalogs (Luo+, 2019)
J/ApJ/697/207 : Cold stellar stream orbit fit (Willett+, 2009)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/other/RAA/11.924 : Atmospheric parameters for 771 stars (Wu+, 2011)
J/A+A/525/A71 : Atmospheric parameters for 1273 stars (Wu+, 2011)
J/other/RAA/17.62 : Candidate members of 4 stellar streams (Li+, 2017)
J/MNRAS/486/2995 : GD-1 stellar stream (Malhan+, 2019)
http://www.sdss.org/ : SDSS home page
http://dr6.lamost.org/ : LAMOST DR6 home page
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- SpID SDSS spectroscopic identifier
(plate-MJD-fiber)
17- 26 F10.6 deg RAdeg [126.5/206] Right Ascension (J2000)
28- 36 F9.6 deg DEdeg [-0.5/58.6] Declination (J2000)
38- 47 F10.6 deg phi1 [-82.1/2.9] Stream-centered φ1
coordinate
49- 57 F9.6 deg phi2 [-2.4/1.1] Stream-centered φ2
coordinate
59- 63 F5.2 mas/yr pmRA [-9.4/-0.8] Proper motion along RA * cos(DE)
65- 70 F6.2 mas/yr pmDE [-14.2/-3] Proper motion along DE
72- 76 F5.2 mag g0mag [14.9/20.3] Intrinsic SDSS g band magnitude
78- 82 F5.2 mag r0mag [14.4/19.9] Intrinsic SDSS r band magnitude
84- 88 F5.2 [-] [Fe/H] [-2.5/-1.8] Metallicity
90- 93 F4.2 [-] e_[Fe/H] [0/1] Uncertainty in [Fe/H]
95-100 F6.1 km/s RVel [-262/264] Radial velocity
102-106 F5.1 km/s e_RVel [7/113] Uncertainty in RVel
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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- 31 A31 --- SpID LAMOST spectral ID
33- 42 F10.6 deg RAdeg [141.5/209.6] Right Ascension (J2000)
44- 52 F9.6 deg DEdeg [26.8/58.5] Declination (J2000)
54- 63 F10.6 deg phi1 [-51.2/4.8] Stream-centered φ1 coordinate
65- 73 F9.6 deg phi2 [-1.9/1.2] Stream-centered φ2 coordinate
75- 79 F5.2 mas/yr pmRA [-7.9/-4.3] Proper motion along RA * cos(DE)
81- 86 F6.2 mas/yr pmDE [-13.4/-2.5] Proper motion along DE
88- 92 F5.2 mag g0mag [13.7/18.2] Intrinsic SDSS g band magnitude
94- 98 F5.2 mag r0mag [12.9/17.8] Intrinsic SDSS r band magnitude
100-104 F5.2 [-] [Fe/H] [-2.5/-1.8] Metallicity
106-109 F4.2 [-] e_[Fe/H] [0.02/0.3] Uncertainty in [Fe/H]
111-116 F6.1 km/s RVel [-279/80] Radial velocity
118-121 F4.1 km/s e_RVel [1/19.5] Uncertainty in RVel
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 31 A31 --- SpID LAMOST spectral ID
33- 42 F10.6 deg RAdeg [140.2/200.6] Right Ascension (J2000)
44- 52 F9.6 deg DEdeg [25.5/58.1] Declination (J2000)
54- 63 F10.6 deg phi1 [-53/-0.01] Stream-centered φ1 coordinate
65- 73 F9.6 deg phi2 [-1.4/0.5] Stream-centered φ2 coordinate
75- 80 F6.1 km/s RVel [-264.7/84.4] Radial velocity
82- 84 F3.1 km/s e_RVel [0.3/5.9] Uncertainty in RVel
86- 88 A3 --- Class BHB or BS star
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- SpID SDSS spectroscopic identifier
(plate-MJD-fiber)
17- 26 F10.6 deg RAdeg [128.6/186.5] Right Ascension (J2000)
28- 36 F9.6 deg DEdeg [3.8/56.7] Declination (J2000)
38- 47 F10.6 deg phi1 [-77.3/-7.6] Stream-centered φ1 coordinate
49- 57 F9.6 deg phi2 [-1.6/0.2] Stream-centered φ2 coordinate
59- 63 F5.2 [-] [Fe/H] [-2.8/-1.4] Metallicitycity
65- 68 F4.2 [-] e_[Fe/H] [0.02/0.3] Uncertainty in [Fe/H]
70- 75 F6.1 km/s RVel [-198/237] Radial velocity
77- 79 F3.1 km/s e_RVel [1.7/9.8] Uncertainty in RVel
81- 83 A3 --- Class BHB or BS star
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 10 F10.6 deg RAdeg [128.6/205.9] Right Ascension (J2000)
12- 20 F9.6 deg DEdeg [3.8/59.5] Declination (J2000)
22- 31 F10.6 deg phi1 [-77.3/3] Stream-centered φ1 coordinate
33- 41 F9.6 deg phi2 [-2.6/1.1] Stream-centered φ2 coordinate
43- 48 F6.3 mas/yr pmRA [-8.6/-0.7] Proper motion along RA * cos(DE)
50- 56 F7.3 mas/yr pmDE [-13.2/-2] Proper motion along DE
58- 63 F6.3 mag g0mag [14.8/18.8] Intrinsic SDSS g band magnitude
65- 70 F6.3 mag r0mag [14.9/18.7] Intrinsic SDSS r band magnitude
72- 75 A4 --- Spec Spectra flag (1)
77- 79 A3 --- Class BHB or BS star
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Note (1): Flag as follows:
L = one or more spectra in LAMOST DR6 in Table 6;
S = one or more spectra in SDSS DR14 in Table 7.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 08-Nov-2019