J/A+A/708/A259 4 MW satellites stars APOGEE abundances (Xu+, 2026)
APOGEE chemical abundances of stars in the MW satellites Fornax, Sextans, Draco
and Carina.
Xu C., Qiao Y., Tang B.T., Fernandez-Trincado J.G., Yan Z.Q., Huang R.Y.,
Geisler D.
<Astron. Astrophys. 708, A259 (2026)>
=2026A&A...708A.259X 2026A&A...708A.259X (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Stars, giant ; Photometry ; Spectroscopy ;
Abundances ; Optical
Keywords: Galaxy: abundances - globular clusters: general - galaxies: dwarf -
Local Group
Abstract:
During its evolution, the Milky Way (MW) incorporated numerous dwarf
galaxies, particularly low-mass systems. The surviving dwarf galaxies
orbiting the MW serve as exceptional laboratories for studying the
unique properties of these systems. Their metalpoor environments and
shallow gravitational potentials likely drive significant differences
in star formation and star cluster properties compared to those in the
MW. Using high-quality near-infrared spectra from the APOGEE survey,
we determined abundances of Fe, C, N, O, Mg, Al, Si, Ca, Ti, Cr, Mn,
Ni, and Ce for 74 stars in four MW satellite dwarf galaxies: Fornax,
Sextans, Draco, and Carina. Our analysis reveals that the distribution
of {alpha] elements (e.g., [Si/Fe]) strongly correlates with galaxy
luminosity (and hence mass), underscoring the critical role of galaxy
mass in shaping chemical evolution. These dwarf galaxies exhibit
[Al/Fe]∼ -0.5, which is comparable to those of the metal-poor stars in
the MW. Additionally, we identified nitrogen-rich field stars in the
Fornax dwarf galaxy, which display distinct metallicities compared to
its known globular clusters (GCs). If these stars originated in GCs
and subsequently escaped, their presence suggests we are observing
relics of destroyed GCs, offering possible evidence of cluster
disruption.
Description:
Table B1 presents primary stellar parameters, observational data and
host galaxy membership for 74 sample stars in four dwarf galaxies
(Fornax, Draco, Carina, and Sextans). Table B2 provides the chemical
abundances ([Fe/H] and various [X/Fe] ratios) for these stars, derived
using the BACCHUS algorithm.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 81 74 Basic information on sample stars
tableb2.dat 80 74 Chemical abundances of sample stars
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq Running number
4- 21 A18 --- APOGEE APOGEE identifier
23- 30 F8.4 deg RAdeg Right Ascension (J2000)
32- 39 F8.4 deg DEdeg Declination (J2000)
41- 44 I4 K Teff Effective temperature
46- 49 F4.2 [cm/s2] logg Surface gravity
51- 54 F4.2 [cm/s2] e_logg Uncertainty in logg
56- 62 F7.2 km/s RV Radial velocity
64- 67 F4.2 km/s e_RV Uncertainty in RV
69- 71 I3 --- S/N Signal-to-noise ratio
73- 77 F5.2 mag Gmag Gaia G-band magnitude
79- 81 A3 --- DGal [Car Dra Fnx Sex] Dwarf galaxy membership
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Byte-by-byte Description of file: tableb2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq Running number
4- 8 F5.2 [-] [Fe/H] Metallicity (Iron abundance relative to H)
10- 14 F5.2 [-] [C/Fe] ?=- Carbon abundance ratio relative to Iron
16- 20 F5.2 [-] [N/Fe] ?=- Nitrogen abundance ratio relative to Iron
22- 26 F5.2 [-] [O/Fe] ?=- Oxygen abundance ratio relative to Iron
28- 32 F5.2 [-] [Mg/Fe] ?=- Magnesium abundance ratio relative to Iron
34- 38 F5.2 [-] [Al/Fe] ?=- Aluminum abundance ratio relative to Iron
40- 44 F5.2 [-] [Si/Fe] ?=- Silicon abundance ratio relative to Iron
46- 50 F5.2 [-] [Ca/Fe] ?=- Calcium abundance ratio relative to Iron
52- 56 F5.2 [-] [Ti/Fe] ?=- Titanium abundance ratio relative to Iron
58- 62 F5.2 [-] [Cr/Fe] ?=- Chromium abundance ratio relative to Iron
64- 68 F5.2 [-] [Mn/Fe] ?=- Manganese abundance ratio relative to Iron
70- 74 F5.2 [-] [Ni/Fe] ?=- Nickel abundance ratio relative to Iron
76- 80 F5.2 [-] [Ce/Fe] ?=- Cerium abundance ratio relative to Iron
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Acknowledgements:
Baitian Tang, tangbt(at)mail.sysu.edu.cn
License: CC-BY-4.0 [see https://spdx.org/licenses/]
(End) Patricia Vannier [CDS] 16-Mar-2026