J/AJ/169/279 Abundances of low-metallicity stars in Sgr dwarf galaxy (Ou+, 2025)
Early r-process enrichment and hierarchical assembly across the Sagittarius
dwarf galaxy
Ou X., Yelland A., Chiti A., Frebel A., Limberg G., Mardini M.K.
<Astron. J., 169, 279 (2025)>
=2025AJ....169..279O 2025AJ....169..279O
ADC_Keywords: Abundances; Galaxies, dwarf; Radial velocities; Photometry;
Optical; Spectra, infrared; Stars, metal-deficient
Keywords: Sagittarius dwarf spheroidal galaxy ; Stellar abundances ;
Chemical enrichment ; R-process ; Galactic archaeology ;
Galaxy chemical evolution
Abstract:
Dwarf galaxies like Sagittarius (Sgr) provide a unique window into the
early stages of galactic chemical evolution, particularly through
their metal-poor stars. By studying the chemical abundances of stars
in the Sgr core and tidal streams, we can gain insights into the
assembly history of this galaxy and its early heavy element
nucleosynthesis processes. We efficiently selected extremely
metal-poor candidates in the core and streams for high-resolution
spectroscopic analysis using metallicity-sensitive photometry from
SkyMapper DR2 and Gaia DR3 XP spectra, and proper motions. We present
a sample of 37 Sgr stars with detailed chemical abundances, of which
we identify 10 extremely metal-poor ([Fe/H]≤-3.0) stars, 25 very
metal-poor ([Fe/H]≤-2.0) stars, and two metal-poor ([Fe/H]≤-1.0)
stars. This sample increases the number of extremely metal-poor Sgr
stars analyzed with high-resolution spectroscopy by a factor of 5. Of
these stars, 15 are identified as members of the Sgr tidal stream,
while the remaining 22 are associated with the core. We derive
abundances for up to 20 elements and identify no statistically
significant differences between the element abundance patterns across
the core and stream samples. Intriguingly, we identify stars that may
have formed in ultrafaint dwarf galaxies that accreted onto Sgr, in
addition to patterns of C and r-process elements distinct from the
Milky Way halo. Over half of the sample shows a neutron-capture
element abundance pattern consistent with the scaled solar pure
r-process pattern, indicating early r-process enrichment in the Sgr
progenitor.
Description:
We used Gaia DR3 (I/355) proper motions to constrain our initial target
selection and ensure a high-purity sample of Sgr member stars in its
core and stream.
Of our target selection, our metal-poor candidates in the Sgr dwarf
galaxy were selected using metallicity-sensitive photometry from
SkyMapper DR2 (Onken+, 2019PASA...36...33O 2019PASA...36...33O) and synthetic photometry
derived from Gaia XP (or flux-calibrated BP/RP) spectra
(Gaia Collab.+2016, 2021, 2023). For targets observed before 2023, we
used photometric metallicities derived from SkyMapper DR2 in
Chiti+2021 (J/ApJS/254/31) to select candidates in the core of Sgr.
We then obtained follow-up high-resolution spectroscopy of ∼20 stars
in the stream and ∼40 stars in the core using the Magellan Clay
6.5m Telescopes at Las Campanas Observatory using the Magellan Inamori
Kyocera Echelle (MIKE) spectrograph in 2021 July and 2023 May and
June. All stars were observed with the 1" slit and 2x2 binning,
yielding a resolving power of R∼28,000/22,000 on the blue/red arm of
MIKE with wavelength coverage 3200-5000 and 4900-10000Å,
respectively.
Our final sample consists of 22 stars with kinematics consistent with
that of the core of Sgr, and 15 stars have properties in agreement
with the kinematic signature of the tidal streams. We measured up to
20 elements, including C, Na I, Mg I, Al I, Si I, Ca I, Sc II, Ti II,
Cr I, Mn I, Co I, Ni I, Zn I, Sr II, Y II, Zr II, Ba II, La II, Eu II,
and Dy II. We note that we do not include the non-LTE correction for
the following species known to be affected by departures from LTE: Na I,
Al I, Cr I, and Mn I. This allows for a more consistent comparison
of our results with those in the literature, which are largely
presented without a non-LTE correction.
Objects:
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RA (2000) DE Designation(s)
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18 55 19.00 -30 32 43.0 NAME SDG = NAME Sagittarius Dwarf Galaxy
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 818 37 Chemical abundances for the Sgr sample
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
J/AJ/113/634 : The survival of Sagittarius dwarf galaxy (Ibata+ 1997)
J/ApJ/655/492 : Equivalent widths of 26 metal-poor stars (Aoki+, 2007)
J/ApJ/701/1053 : Abundances of 8 stars in the Draco dSph (Cohen+, 2009)
J/ApJ/724/341 : Nucleosynthesis of massive metal-free stars (Heger+, 2010)
J/ApJ/724/975 : Heavy elements abundances of metal-poor stars (Roederer+, 2010)
J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)
J/AJ/144/4 : Properties of dwarf gal. in the Local Group (McConnachie+, 2012)
J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013)
J/ApJ/779/102 : Metallicities of RGB stars in dwarf galaxies (Kirby+, 2013)
J/ApJ/797/21 : Carbon-enhanced metal-poor stars (Placco+, 2014)
J/ApJ/847/142 : Ultra-metal-poor stars LTE & NLTE abundances (Ezzeddine+, 2017)
J/ApJ/838/44 : Abundances of the brightest member of Tuc III (Hansen+, 2017)
J/ApJ/838/11 : Member stars in the MW satellite Tucana III (Simon+, 2017)
J/ApJ/855/83 : Abund. of very metal-poor stars in Sagittarius (Hansen+, 2018)
J/AJ/156/179 : Highly r-process-enhanced field stars kinem. (Roederer+, 2018)
J/ApJ/870/83 : Abund. in the ultra-faint dwarf gal. GruI & TriII (Ji+, 2019)
J/ApJ/882/177 : Abundances of 4 member stars of Tucana III (Marshall+, 2019)
J/A+A/631/A171 : Neutron-capture elements in dwarf gal. (Skuladottir+, 2019)
J/ApJ/898/150 : High-res. MIKE obs. of metal-poor stars (Ezzeddine+, 2020)
J/ApJ/897/183 : Chem. abundances of 3 stars in Grus II galaxy (Hansen+, 2020)
J/ApJ/889/63 : Properties of Sgr Stars (Hayes+, 2020)
J/ApJS/249/30 : R-Process Alliance: metal-poor star spectr. (Holmbeck+, 2020)
J/AJ/160/181 : Chemical abundances in red giants with Magellan (Ji+, 2020)
J/ApJ/892/137 : Spectroscopy of Grus II, Tuc IV and Tuc V (Simon+, 2020)
J/ApJS/254/31 : Phot. metallicities of stars in SkyMapper DR2 (Chiti+, 2021)
J/MNRAS/501/2279 : Stars in the Sagittarius stream (Vasiliev+, 2021)
J/A+A/666/A64 : Sagittarius stream with eDR3 (Ramos+, 2022)
J/A+A/674/A33 : Gaia synthetic phot. cat. of white dwarfs (Gaia Coll., 2023)
J/A+A/691/A226 : Abundances of globular cluster stars (Ceccarelli+, 2024)
J/A+A/691/A333 : Gaia-Sausage-Enceladus abundances (Ernandes+, 2024)
J/A+A/692/A115 : Pristine survey DR1 (Martin+, 2024)
J/A+A/690/A333 : Pristine Inner Galaxy Survey. X. (Sestito+, 2024)
J/A+A/689/A201 : Pristine Inner Galaxy Survey. IX. (Sestito+, 2024)
J/MNRAS/537/1984 : CEMP prediction abundances (Ardern-Arentsen+, 2025)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 (I/355) source ID
21- 26 A6 --- Name Short target name used in this study
28- 38 F11.7 deg RAdeg Gaia DR3 right accension (ICRS, J2016)
40- 48 F9.5 deg DEdeg Gaia DR3 declination (ICRS, J2016)
50- 55 F6.2 deg Lambda Longitude in the heliocentric Sgr
coordinate system (1)
57- 62 F6.2 deg Beta Latitude in the heliocentric Sgr
coordinate system (1)
64- 69 A6 --- Mem Classification of the whether the star
belongs to the Sgr core or stream (2)
71- 76 F6.1 km/s RVobs [-198.1/219.9] Observed radial velocity
78- 83 F6.2 km/s corrRVhel [-28.97/20.37] Heliocentric radial
velocity correction
85- 90 F6.1 km/s RVhel [-218.0/193.0] Corrected radial velocity
92- 101 A10 "Y:M:D" UTDate UTC date of the observation, YYYY-MM-DD
103- 107 I5 s UTTime [876/85938] UTC time stamp
109- 111 A3 --- Bin [2x2] Binning during exposure readout
113- 116 I4 s ExpTime [600/5999] Total exposure time
118- 120 F3.1 arcsec Slit [1.0] Spectrum slit width
122- 125 I4 K TeffPh [4280/5274] Photometric effective
temperature
127- 130 F4.2 [cm/s2] loggPh [0.4/2.6] Photometric surface gravity
132- 136 F5.2 [Sun] mZPh [-3.3/-1.79] Photometric model
metallicity
138- 141 F4.2 km/s VtPh [1.38/2.51] Photometric microturbulence
143- 145 I3 K e_TeffPh [122/123] Uncertainty for photometric
effective temperature
147- 150 F4.2 [cm/s2] e_loggPh [0.2/0.21] Uncertainty for photometric
surface gravity
152- 155 F4.2 [Sun] e_mZPh [0.21/0.34] Uncertainty for photometric
model metallicity
157- 160 F4.2 km/s e_VtPh [0.25/0.58] Uncertainty for photometric
microturbulence
162- 167 F6.1 K TeffSp [4180/5200] Spectroscopic effective
temperature
169- 172 F4.2 [cm/s2] loggSp [0.05/2.55] Spectroscopic surface
gravity
174- 177 F4.2 km/s VtSp [1.97/4.5] Spectroscopic microturbulence
179- 183 F5.2 [Sun] mZSp [-3.7/-2.1] Spectroscopic model
metallicity
185- 189 F5.2 [Sun] [EuII/MgI] [-0.74/0.64]? Relative abundance,
[EuII/MgI]
191- 194 F4.2 [Sun] e_[EuII/MgI] [0.13/0.29]? Uncertainty for [EuII/MgI]
196- 200 F5.2 [Sun] [EuII/FeII] [-0.58/1.14]? Relative abundance,
[EuII/FeII]
202- 205 F4.2 [Sun] e_[EuII/FeII] [0.06/0.19]? Uncertainty for [EuII/FeII]
207- 211 F5.2 [Sun] [SrII/BaII] [-0.82/1.66] Relative abundance,
[SrII/BaII]
213- 216 F4.2 [Sun] e_[SrII/BaII] [0.05/0.4] Uncertainty for [SrII/BaII]
218- 222 F5.2 [Sun] [SrII/MgI] [-1.7/1.08] Relative abundance,
[SrII/MgI]
224- 227 F4.2 [Sun] e_[SrII/MgI] [0.14/0.34] Uncertainty for [SrII/MgI]
229- 232 F4.2 [Sun] [EuII/BaII] [0.24/0.78]? Relative abundance,
[EuII/BaII]
234- 237 F4.2 [Sun] e_[EuII/BaII] [0.06/0.23]? Uncertainty for [EuII/BaII]
239- 243 F5.2 [Sun] [EuII/SrII] [-0.58/0.88]? Relative abundance,
[EuII/SrII]
245- 248 F4.2 [Sun] e_[EuII/SrII] [0.12/0.33]? Uncertainty for [EuII/SrII]
250- 254 F5.2 [Sun] [C/Fe] [-0.88/0.2] Relative abundance, [C/Fe]
256- 259 F4.2 [Sun] e_[C/Fe] [0.15/0.28] Uncertainty for [C/Fe]
261- 265 F5.2 [Sun] corr[C/Fe] [-0.58/0.84] Evolution-corrected (based
on Placco+2014, J/ApJ/797/21) relative
abundance, [C/Fe]
267- 271 F5.2 [Sun] [NaI/Fe] [-0.56/0.97] Relative abundance,
[NaI/Fe]
273- 276 F4.2 [Sun] e_[NaI/Fe] [0.04/0.18] Uncertainty for [NaI/Fe]
278- 282 F5.2 [Sun] [MgI/Fe] [-0.21/0.5] Relative abundance, [MgI/Fe]
284- 287 F4.2 [Sun] e_[MgI/Fe] [0.05/0.16] Uncertainty for [Mg I/Fe]
289- 293 F5.2 [Sun] [AlI/Fe] [-1.46/0.15]? Relative abundance,
[AlI/Fe]
295- 298 F4.2 [Sun] e_[AlI/Fe] [0.08/0.39]? Uncertainty for [AlI/Fe]
300- 303 F4.2 [Sun] [SiI/Fe] [0.02/0.93] Relative abundance, [SiI/Fe]
305- 308 F4.2 [Sun] e_[SiI/Fe] [0.04/0.26] Uncertainty for [SiI/Fe]
310- 314 F5.2 [Sun] [CaI/Fe] [-0.06/0.48] Relative abundance,
[CaI/Fe]
316- 319 F4.2 [Sun] e_[CaI/Fe] [0.04/0.13] Uncertainty for [CaI/Fe]
321- 325 F5.2 [Sun] [ScII/Fe] [-0.48/0.23] Relative abundance,
[ScII/Fe]
327- 330 F4.2 [Sun] e_[ScII/Fe] [0.04/0.23] Uncertainty for [ScII/Fe]
332- 336 F5.2 [Sun] [TiII/Fe] [-0.01/0.41] Relative abundance,
[TiII/Fe]
338- 341 F4.2 [Sun] e_[TiII/Fe] [0.06/0.21] Uncertainty for [TiII/Fe]
343- 347 F5.2 [Sun] [CrI/Fe] [-0.62/-0.1] Relative abundance,
[CrI/Fe]
349- 352 F4.2 [Sun] e_[CrI/Fe] [0.05/0.19] Uncertainty for [CrI/Fe]
354- 358 F5.2 [Sun] [CrII/Fe] [-0.32/0.2]? Relative abundance,
[CrII/Fe]
360- 363 F4.2 [Sun] e_[CrII/Fe] [0.04/0.18]? Uncertainty for [CrII/Fe]
365- 369 F5.2 [Sun] [MnI/Fe] [-0.77/-0.18]? Relative abundance,
[MnI/Fe]
371- 374 F4.2 [Sun] e_[MnI/Fe] [0.08/0.16]? Uncertainty for [MnI/Fe]
376- 380 F5.2 [Sun] [CoI/Fe] [-0.45/0.58]? Relative abundance,
[CoI/Fe]
382- 385 F4.2 [Sun] e_[CoI/Fe] [0.05/0.42]? Uncertainty for [CoI/Fe]
387- 391 F5.2 [Sun] [NiI/Fe] [-0.27/0.37] Relative abundance,
[NiI/Fe]
393- 396 F4.2 [Sun] e_[NiI/Fe] [0.03/0.18] Uncertainty for [NiI/Fe]
398- 402 F5.2 [Sun] [ZnI/Fe] [-0.3/0.99]? Relative abundance,
[ZnI/Fe]
404- 407 F4.2 [Sun] e_[ZnI/Fe] [0.06/0.28]? Uncertainty for [ZnI/Fe]
409- 413 F5.2 [Sun] [SrII/Fe] [-1.37/1.03] Relative abundance,
[SrII/Fe]
415- 418 F4.2 [Sun] e_[SrII/Fe] [0.11/0.36] Uncertainty for [SrII/Fe]
420- 424 F5.2 [Sun] [YII/Fe] [-0.77/0.32] Relative abundance,
[YII/Fe]
426- 429 F4.2 [Sun] e_[YII/Fe] [0.07/0.2]? Uncertainty for [YII/Fe]
431- 435 F5.2 [Sun] [ZrII/Fe] [-0.38/0.52] Relative abundance,
[ZrII/Fe]
437- 440 F4.2 [Sun] e_[ZrII/Fe] [0.04/0.14]? Uncertainty for [ZrII/Fe]
442- 446 F5.2 [Sun] [BaII/Fe] [-1.42/0.47] Relative abundance,
[BaII/Fe]
448- 451 F4.2 [Sun] e_[BaII/Fe] [0.05/0.22] Uncertainty for [BaII/Fe]
453- 457 F5.2 [Sun] [LaII/Fe] [-0.49/0.69]? Relative abundance,
[LaII/Fe]
459- 462 F4.2 [Sun] e_[LaII/Fe] [0.07/0.18]? Uncertainty for [LaII/Fe]
464- 468 F5.2 [Sun] [EuII/Fe] [-0.58/1.14] Relative abundance,
[EuII/Fe]
470- 473 F4.2 [Sun] e_[EuII/Fe] [0.06/0.19]? Uncertainty for [EuII/Fe]
475- 479 F5.2 [Sun] [DyII/Fe] [-0.17/1.49] Relative abundance,
[DyII/Fe]
481- 484 F4.2 [Sun] e_[DyII/Fe] [0.07/0.17]? Uncertainty for [DyII/Fe]
486- 490 F5.2 [Sun] [C/H] [-3.95/-2.33] Relative abundance, [C/H]
492- 495 F4.2 [Sun] e_[C/H] [0.1/0.33] Uncertainty for [C/H]
497- 501 F5.2 [Sun] [NaI/H] [-3.1/-1.7] Relative abundance, [NaI/H]
503- 506 F4.2 [Sun] e_[NaI/H] [0.16/0.38] Uncertainty for [NaI/H]
508- 512 F5.2 [Sun] [MgI/H] [-3.27/-1.75] Relative abundance,
[MgI/H]
514- 517 F4.2 [Sun] e_[MgI/H] [0.09/0.29] Uncertainty for [MgI/H]
519- 523 F5.2 [Sun] [AlI/H] [-4.07/-2.52]? Relative abundance,
[AlI/H]
525- 528 F4.2 [Sun] e_[AlI/H] [0.1/0.5]? Uncertainty for [AlI/H]
530- 534 F5.2 [Sun] [SiI/H] [-2.69/-1.51] Relative abundance,
[SiI/H]
536- 539 F4.2 [Sun] e_[SiI/H] [0.16/0.32] Uncertainty for [SiI/H]
541- 545 F5.2 [Sun] [CaI/H] [-3.02/-1.48] Relative abundance,
[CaI/H]
547- 550 F4.2 [Sun] e_[CaI/H] [0.06/0.21] Uncertainty for [CaI/H]
552- 556 F5.2 [Sun] [ScII/H] [-3.1/-1.71] Relative abundance,
[ScII/H]
558- 561 F4.2 [Sun] e_[ScII/H] [0.07/0.26] Uncertainty for [ScII/H]
563- 567 F5.2 [Sun] [TiII/H] [-3.01/-1.27] Relative abundance,
[TiII/H]
569- 572 F4.2 [Sun] e_[TiII/H] [0.1/0.24] Uncertainty for [TiII/H]
574- 578 F5.2 [Sun] [CrI/H] [-3.78/-2.01] Relative abundance,
[CrI/H]
580- 583 F4.2 [Sun] e_[CrI/H] [0.11/0.38] Uncertainty for [CrI/H]
585- 589 F5.2 [Sun] [CrII/H] [-3.13/-1.64]? Relative abundance,
[CrII/H]
591- 594 F4.2 [Sun] e_[CrII/H] [0.07/0.2]? Uncertainty for [CrII/H]
596- 600 F5.2 [Sun] [MnI/H] [-3.9/-2.32]? Relative abundance,
[MnI/H]
602- 605 F4.2 [Sun] e_[MnI/H] [0.05/0.15]? Uncertainty for [MnI/H]
607- 611 F5.2 [Sun] [CoI/H] [-3.26/-1.79]? Relative abundance,
[CoI/H]
613- 616 F4.2 [Sun] e_[CoI/H] [0.1/0.35]? Uncertainty for [CoI/H]
618- 622 F5.2 [Sun] [NiI/H] [-3.38/-1.85] Relative abundance,
[NiI/H]
624- 627 F4.2 [Sun] e_[NiI/H] [0.09/0.28] Uncertainty for [NiI/H]
629- 633 F5.2 [Sun] [ZnI/H] [-3.08/-1.79]? Relative abundance,
[ZnI/H]
635- 638 F4.2 [Sun] e_[ZnI/H] [0.03/0.09]? Uncertainty for [ZnI/H]
640- 644 F5.2 [Sun] [SrII/H] [-4.51/-1.66] Relative abundance,
[SrII/H]
646- 649 F4.2 [Sun] e_[SrII/H] [0.12/0.46] Uncertainty for [SrII/H]
651- 655 F5.2 [Sun] [YII/H] [-3.66/-2.01] Relative abundance,
[YII/H]
657- 660 F4.2 [Sun] e_[YII/H] [0.07/0.19]? Uncertainty for [YII/H]
662- 666 F5.2 [Sun] [ZrII/H] [-3.16/-1.46] Relative abundance,
[ZrII/H]
668- 671 F4.2 [Sun] e_[ZrII/H] [0.06/0.19]? Uncertainty for [ZrII/H]
673- 677 F5.2 [Sun] [BaII/H] [-4.58/-1.5] Relative abundance,
[BaII/H]
679- 682 F4.2 [Sun] e_[BaII/H] [0.07/0.24] Uncertainty for [BaII/H]
684- 688 F5.2 [Sun] [LaII/H] [-3.13/-1.47]? Relative abundance,
[LaII/H]
690- 693 F4.2 [Sun] e_[LaII/H] [0.06/0.15]? Uncertainty for [LaII/H]
695- 699 F5.2 [Sun] [EuII/H] [-3.25/-1.11] Relative abundance,
[EuII/H]
701- 704 F4.2 [Sun] e_[EuII/H] [0.06/0.16]? Uncertainty for [EuII/H]
706- 710 F5.2 [Sun] [DyII/H] [-3.06/-1.07] Relative abundance,
[DyII/H]
712- 715 F4.2 [Sun] e_[DyII/H] [0.07/0.18]? Uncertainty for [DyII/H]
717- 721 F5.2 [Sun] [Fe/H] [-3.29/-1.85] Relative abundance, [Fe/H]
723- 726 F4.2 [Sun] e_[Fe/H] [0.08/0.24] Uncertainty for [Fe/H]
728- 732 F5.2 [Sun] [alpha/Fe] [-0.06/0.52] Relative abundance,
[alpha/Fe]
734 A1 --- l_[C/Fe] Upper limit flag for [C/Fe]
736 A1 --- l_[NaI/Fe] Upper limit flag for [NaI/Fe]
738 A1 --- l_[MgI/Fe] Upper limit flag for [MgI/Fe]
740 A1 --- l_[AlI/Fe] Upper limit flag for [AlI/Fe]
742 A1 --- l_[SiI/Fe] Upper limit flag for [SiI/Fe]
744 A1 --- l_[CaI/Fe] Upper limit flag for [CaI/Fe]
746 A1 --- l_[ScII/Fe] Upper limit flag for [ScII/Fe]
748 A1 --- l_[TiII/Fe] Upper limit flag for [TiII/Fe]
750 A1 --- l_[CrI/Fe] Upper limit flag for [CrI/Fe]
752 A1 --- l_[CrII/Fe] Upper limit flag for [CrII/Fe]
754 A1 --- l_[MnI/Fe] Upper limit flag for [MnI/Fe]
756 A1 --- l_[CoI/Fe] Upper limit flag for [CoI/Fe]
758 A1 --- l_[NiI/Fe] Upper limit flag for [NiI/Fe]
760 A1 --- l_[ZnI/Fe] Upper limit flag for [ZnI/Fe]
762 A1 --- l_[SrII/Fe] Upper limit flag for [SrII/Fe]
764 A1 --- l_[YII/Fe] Upper limit flag for [YII/Fe]
766 A1 --- l_[ZrII/Fe] Upper limit flag for [ZrII/Fe]
768 A1 --- l_[BaII/Fe] Upper limit flag for [BaII/Fe]
770 A1 --- l_[LaII/Fe] Upper limit flag for [LaII/Fe]
772 A1 --- l_[EuII/Fe] Upper limit flag for [EuII/Fe]
774 A1 --- l_[DyII/Fe] Upper limit flag for [DyII/Fe]
776 A1 --- l_[C/H] Upper limit flag for [C/H]
778 A1 --- l_[NaI/H] Upper limit flag for [NaI/H]
780 A1 --- l_[MgI/H] Upper limit flag for [MgI/H]
782 A1 --- l_[AlI/H] Upper limit flag for [AlI/H]
784 A1 --- l_[SiI/H] Upper limit flag for [SiI/H]
786 A1 --- l_[CaI/H] Upper limit flag for [CaI/H]
788 A1 --- l_[ScII/H] Upper limit flag for [ScII/H]
790 A1 --- l_[TiII/H] Upper limit flag for [TiII/H]
792 A1 --- l_[CrI/H] Upper limit flag for [CrI/H]
794 A1 --- l_[CrII/H] Upper limit flag for [CrII/H]
796 A1 --- l_[MnI/H] Upper limit flag for [MnI/H]
798 A1 --- l_[CoI/H] Upper limit flag for [CoI/H]
800 A1 --- l_[NiI/H] Upper limit flag for [NiI/H]
802 A1 --- l_[ZnI/H] Upper limit flag for [ZnI/H]
804 A1 --- l_[SrII/H] Upper limit flag for [SrII/H]
806 A1 --- l_[YII/H] Upper limit flag for [YII/H]
808 A1 --- l_[ZrII/H] Upper limit flag for [ZrII/H]
810 A1 --- l_[BaII/H] Upper limit flag for [BaII/H]
812 A1 --- l_[LaII/H] Upper limit flag for [LaII/H]
814 A1 --- l_[EuII/H] Upper limit flag for [EuII/H]
816 A1 --- l_[DyII/H] Upper limit flag for [DyII/H]
818 A1 --- l_[alpha/Fe] Upper limit flag for [alpha/Fe]
--------------------------------------------------------------------------------
Note (1): The longitude, Λ☉, is centered on the Sgr core
(Λ☉=0°) and increases in the direction of the trailing Sgr
debris, whereas the latitude, Β☉, is aligned with the debris
midplane and positive toward the orbital pole
(lGC,bGC)=(273.8°,-13.5°). We take the Sgr core to be located at
Galactic coordinates (l,b)=(5.6°,-14.2°) and Sgr coordinates
(Λ☉,Β☉)=(0,0) (Majewski+, 2003ApJ...599.1082M 2003ApJ...599.1082M).
Note (2): The core membership is constrained to the stars within six degrees of
the core. Membership as follows:
core = 22 occurrences
stream = 15 occurrences
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Robin Leichtnam [CDS] 18-Feb-2026