J/A+A/700/A13 GD-1 and Kshir tidal streams metallicity and motion (Shi+, 2025)
Metallicity and motion of GD-1 and Kshir tidal streams.
Shi W.B., Liu Z.S., Chen Y.Q., Zhao J.K., Zhao G., Li G.W., Wang P.,
Yan H.H., Wu X.H.
<Astron. Astrophys. 700, A13 (2025)>
=2025A&A...700A..13S 2025A&A...700A..13S (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, giant ; Radial velocities ;
Abundances, [Fe/H] ; Optical
Keywords: stars: abundances - Galaxy: evolution - Galaxy: halo -
Galaxy: structure
Abstract:
To explore the metallicity and kinematic properties of stellar
streams, we selected the members of the GD-1 stream and Kshir stream,
and conducted out a detailed analysis of the member stars of the
stellar streams. By utilizing the spectral data from LAMOST DR10 and
SDSS DR16, and integrating them with the astrometric data from Gaia
DR3, we identified the member stars of the stellar streams through an
analysis of their geometric space, velocity space, and metallicity
properties. Based on these identified member stars, we discovered and
summarized the metallicity and kinematic properties of the stellar
streams. 152 members and 68 members were identified in the GD-1
stream and the Kshir stream, respectively. The average metallicity of
the GD-1 stream is [Fe/H]=-2.19±0.10dex. The known gaps at
phi1=-20° and phi1=-40° were confirmed, and a possible new
gap at phi1=-60° was found. For the first time, we found that
the formation reasons of the gaps are that there is a large velocity
difference on both sides of the gaps and the velocities at both ends
of the stream are reversed. These velocity characteristics may be due
to the gaps being near a "turnaround" point in the stream orbit,
or the stellar stream was significantly impacted by the massive
Sagittarius 3Gyr ago. The average metallicity of the Kshir stream is
[Fe/H]=-1.65±0.13dex. The radial velocity and proper-motion
distributions along the Kshir stream are consistent with those of the
GD-1 stream. Presumably, they are orbital wraps of the same
structure.
Description:
Using spectroscopic data from LAMOST DR10 and SDSS DR16, along with
photometric data from SDSS DR16 and astrometric data from Gaia DR3, we
constrained the position, velocity, proper motion, and metallicity of
the GD-1 and Kshir stellar streams. Using this method, we identified a
total of 152 members in the GD-1 stream and 68 members in the Kshir
stream.
We list 152 members of GD-1 stream in Table A1 and 68 members of Kshir
stream in Table A2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 89 152 The members of GD-1 stream
tablea2.dat 75 68 The members of Kshir stream
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See also:
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
V/156 : LAMOST DR7 catalogs (Luo+, 2019)
J/ApJ/869/122 : SDSS-DR14 and LAMOST DR6 spectra in GD-1 stream (Li+, 2018)
J/ApJ/877/13 : Member stars of the GD-1 tidal stream (Huang+, 2019)
J/MNRAS/486/2995 : GD-1 stellar stream (Malhan+, 2019)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 7 F7.3 deg RAdeg Right ascension (J2000)
9- 15 F7.3 deg DEdeg Declination (J2000)
17- 24 F8.3 km/s RV Radial velocity
26- 31 F6.3 [-] [Fe/H] ?=- Metallicity
33- 39 F7.3 deg phi1 The GD-1 coordinate system
41- 46 F6.3 deg phi2 The GD-1 coordinate system
48- 53 F6.3 mas/yr pmRA Proper motion along right ascension
55- 61 F7.3 mas/yr pmDE Proper motion along declination
63- 70 F8.3 km/s Vgsr The velocity in the Galactic standard of rest
72- 77 F6.3 kpc modDst Model distance
79- 85 F7.3 km/s VT Tangential velocity
87 A1 --- Mark1 [LS] LAMOST or SDSS
89 A1 --- Mark2 [N] N for newly
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 7 F7.3 deg RAdeg Right Ascension (J2000)
9- 15 F7.3 deg DEdeg Declination (J2000)
17- 24 F8.3 km/s RV Radial velocity
26- 31 F6.3 [-] [Fe/H] ?=- Metallicity
33- 39 F7.3 deg phi1 The GD-1 coordinate system
41- 47 F7.3 deg phi2 The GD-1 coordinate system
49- 54 F6.3 mas/yr pmRA Proper motion along right ascension
56- 62 F7.3 mas/yr pmDE Proper motion along Declination
64- 71 F8.3 km/s Vgsr The velocity in the Galactic standard of rest
73 A1 --- Mark1 [LS] LAMOST or SDSS
75 A1 --- Mark2 [N] N for newly
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Acknowledgements:
Weibin Shi, swb(at)bao.ac.cn
(End) Patricia Vannier [CDS] 30-Jun-2025