J/AJ/169/172 Derived parameters & abundances of metal-poor stars (Mittal+, 2025)
New stellar parameters, metallicities, and elemental abundance ratios for 311
metal-poor stars.
Mittal S., Roederer I.U.
<Astron. J., 169, 172 (2025)>
=2025AJ....169..172M 2025AJ....169..172M
ADC_Keywords: Stars, metal-deficient; Abundances, peculiar; Optical;
Photometry, infrared; Equivalent widths; Abundances, [Fe/H]
Keywords: Nucleosynthesis ; Population II stars ; Stellar abundances ;
Stellar astronomy
Abstract:
We present equivalent widths, improved model atmosphere parameters,
and revised abundances for 14 species of 11 elements derived from
high-resolution optical spectroscopy of 311 metal-poor stars. All of
these stars had their parameters previously published by Roederer et
al. We use color-Teff relationships calibrated for Gaia and 2MASS
photometry to calculate improved effective temperatures (Teff). We
calculate log of surface gravity (log g) values using measurements
derived from Gaia parallaxes and other fundamental stellar properties.
We perform a standard LTE abundance analysis using MARCS model
atmospheres and the MOOG line analysis software to rederive
microturbulence velocity parameters, metallicities, and abundances
based on O i, Na i, Mg i, Si i, K i, Ca i, Ti i, Ti ii, Cr i, Cr ii,
Fe i, Fe ii, Ni i, and Zn i lines using previously measured equivalent
widths. On average, the new Teff values are 310K warmer, the new log g
values are higher by 0.64dex, and the new [Fe/H] values are higher by
0.26dex. We apply NLTE corrections to the abundances derived from O i,
Na i, Mg i, Si i, K i, Fe i, and Fe ii lines. Our sample contains 6
stars with [Fe/H]←3.5, 28 stars with [Fe/H]←3.0, and 113 stars with
[Fe/H]←2.5. Our revised abundances for these 311 stars are now in
better agreement with those derived by previous studies of smaller
samples of metal-poor stars in the Milky Way.
Description:
We started with the sample published by Roederer+2014 (J/AJ/147/136).
We used the CDS XMatch (Pineau+, 2020ASPC..522..125P 2020ASPC..522..125P) service to cross
reference these stars with the Gaia mission's third data release (DR3,
I/355), near-infrared 2MASS photometric survey (II/246), EDR3
Corrected Distances catalog (Bailer-Jones+2021, I/352), and the
reddening estimates from Schlafly+ (2011ApJ...737..103S 2011ApJ...737..103S) available
through the NASA/IPAC Infrared Science Archive.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 65 311 Effective temperatures calculated from different
colors
table2.dat 46 47921 Derived line-by-line abundances
table3.dat 73 311 Final effective temperature and log of surface
gravity values, and other final model atmosphere
parameters
table4.dat 271 311 Derived local thermodynamic equilibrium (LTE)
abundances
table5.dat 143 311 Derived non-local thermodynamic equilibrium (NLTE)
abundances
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See also:
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/A+A/416/1117 : Abundances in the early Galaxy (Cayrel+, 2004)
J/A+A/435/373 : Broadening of Fe II lines by H collisions (Barklem+, 2005)
J/ApJ/681/1524 : Detailed abundances for 28 metal-poor stars (Lai+, 2008)
J/A+A/512/A54 : Teff and Fbol from Infrared Flux Method (Casagrande+, 2010)
J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)
J/ApJ/762/26 : Most metal-poor stars. II. 190 Gal. halo stars (Yong+, 2013)
J/AJ/147/136 : Stars of very low metal abundance. VI. Abund. (Roederer+, 2014)
J/ApJ/807/171 : SkyMapper Survey metal-poor star spectroscopy (Jacobson+, 2015)
J/A+A/616/A10 : 46 open clusters GaiaDR2 HR diagrams (Gaia Collaboration, 2018)
J/ApJ/865/129 : Abundance analysis of HD 222925 (Roederer+, 2018)
J/AJ/160/181 : Chemical abundances in red giants with Magellan (Ji+, 2020)
J/A+A/674/A18 : Gaia DR3. The RR Lyrae sample (Clementini+, 2023)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Stellar identifier
14- 17 I4 K T(BP-RP) [4490/7533] Effective temperature from color
BP-RP
19- 21 I3 K e_T(BP-RP) [64/233] Uncertainty in T (BP-RP)
23- 26 I4 K T(BP-G) [0/7214] Effective temperature from color
BP-G (1)
28- 30 I3 K e_T(BP-G) [0/415] Uncertainty in T (BP-G) (1)
32- 35 I4 K T(G-RP) [0/7489] Effective temperature from color
G-RP (1)
37- 39 I3 K e_T(G-RP) [0/224] Uncertainty in T (G-RP) (1)
41- 44 I4 K T(BP-K) [4463/7451] Effective temperature from color
BP-K
46- 48 I3 K e_T(BP-K) [49/144] Uncertainty in T (BP-K)
50- 53 I4 K T(RP-K) [4463/7630] Effective temperature from color
RP-K
55- 57 I3 K e_T(RP-K) [65/242] Uncertainty in T (RP-K)
59- 62 I4 K T(G-K) [0/7644] Effective temperature from color G-K
(1)
64- 65 I2 K e_T(G-K) [0/99] Uncertainty in T (G-K) (1)
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Note (1): Temperatures for G190-010 and HD-219617 did not make use
of Gaia G band photometry so these are set to zero.
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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- 12 A12 --- Name Stellar identifier
14- 20 A7 --- ID Species
22- 29 F8.3 0.1nm lambda [3329.4/7775.4] Wavelength in Angstroms
31- 35 F5.1 0.1pm EW [1.6/476.6] Equivalent width in milliAngstroms
37- 40 F4.2 [-] loge(X) [0.81/8.72] Log epsilon abundance of element X
42- 46 F5.2 --- NLTEcorr [-0.68/0.32]? NLTE correction to log(e)(X)
abundance
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Stellar identifier
14- 15 A2 --- Class Star class (1)
17- 20 I4 K Teff [4472/7451] Effective temperature
22- 23 I2 K e_Teff [2/36] Uncertainty in Teff
25- 28 F4.2 [cm/s2] logg [1.08/4.82] Log of surface gravity
30- 33 F4.2 [cm/s2] e_logg [0.15/0.5] Uncertainty in logg
35- 38 F4.2 mag E(B-V) [0.0/0.22] E(B-V) reddening
40- 43 F4.2 mag e_E(B-V) [0.01/0.03] Uncertainty in E(B-V)
45- 49 F5.2 mag BC-G [-0.62/0.04] Bolometric correction in G
51- 54 F4.2 mag e_BC-G [0.01/0.18] Uncertainty in BC
56- 59 F4.1 [-] [M/H] [-3.9/-1.0] Model metallicity adopted
61- 63 F3.1 [-] e_[M/H] [0.3/0.3] Uncertainty in [M/H]
65- 68 F4.2 km/s vt [0.8/3.5] Microturbulence velocity
70- 73 F4.2 km/s e_vt [0.06/0.06] Uncertainty in vt
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Note (1): Star class as follows:
BS = Blue Straggler-like stars warmer than the main sequence turnoff
(1 occurrence)
HB = stars on the Horizontal Branch (35 occurrences)
MS = stars on the Main Sequence (143 occurrences)
RG = stars on the Red Giant branch (78 occurrences)
SG = stars on the SubGiant branch (54 occurrences)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Stellar identifier
14- 16 I3 --- nFeI [19/138] Number of FeI LTE lines used (1)
18- 21 F4.2 [-] loge(FeI) [3.38/6.46] Log epsilon mean abundance of
FeI
23- 27 F5.2 [-] [FeI/H] [-4.12/-1.04] FeI abundance relative to H
29- 32 F4.2 [-] e_[FeI/H] [0.03/0.1] Total uncertainty in [FeI/H]
34- 35 I2 --- nFeII [1/13]? Number of FeII LTE lines used (1)
37- 40 F4.2 [-] loge(FeII) [3.41/6.52]? Log epsilon mean abundance of
FeII
42- 46 F5.2 [-] [FeII/H] [-4.09/-0.98]? FeII abundance relative to H
48- 51 F4.2 [-] e_[FeII/H] [0.12/0.6]? Total uncertainty in [FeII/H]
53 I1 --- nOI [1/4]? Number of OI LTE lines used (1)
55- 58 F4.2 [-] loge(OI) [6.55/8.72]? Log epsilon mean abundance of
OI
60- 63 F4.2 [-] [OI/Fe] [0.26/2.85]? OI abundance relative to FeI
65- 68 F4.2 [-] e_[OI/Fe] [0.09/0.31]? Total uncertainty in [OI/Fe]
70 I1 --- nNaI [1/4]? Number of NaI LTE lines used (1)
72- 75 F4.2 [-] loge(NaI) [2.42/5.33]? Log epsilon mean abundance of
NaI
77- 81 F5.2 [-] [NaI/Fe] [-0.56/1.63]? NaI abundance relative to FeI
83- 86 F4.2 [-] e_[NaI/Fe] [0.12/0.28]? Total uncertainty in [NaI/Fe]
88 I1 --- nMgI [1/9] Number of MgI LTE lines used (1)
90- 93 F4.2 [-] loge(MgI) [3.81/7.18] Log epsilon mean abundance of
MgI
95- 99 F5.2 [-] [MgI/Fe] [-0.36/1.51] MgI abundance relative to FeI
101- 104 F4.2 [-] e_[MgI/Fe] [0.08/0.22] Total uncertainty in [MgI/Fe]
106 I1 --- nSiI [1/4]? Number of SiI LTE lines used (1)
108- 111 F4.2 [-] loge(SiI) [3.63/6.87]? Log epsilon mean abundance of
SiI
113- 117 F5.2 [-] [SiI/Fe] [-0.34/1.14]? SiI abundance relative to FeI
119- 122 F4.2 [-] e_[SiI/Fe] [0.09/0.55]? Total uncertainty in [SiI/Fe]
124 I1 --- nKI [1/2]? Number of KI LTE lines used (1)
126- 129 F4.2 [-] loge(KI) [1.51/4.74]? Log epsilon mean abundance of
KI
131- 135 F5.2 [-] [KI/Fe] [-0.08/0.88]? KI abundance relative to FeI
137- 140 F4.2 [-] e_[KI/Fe] [0.11/0.21]? Total uncertainty in [KI/Fe]
142- 143 I2 --- nCaI [3/14] Number of CaI LTE lines used
145- 148 F4.2 [-] loge(CaI) [2.45/5.58] Log epsilon mean abundance of
CaI
150- 154 F5.2 [-] [CaI/Fe] [-0.32/0.54] CaI abundance relative to FeI
156- 159 F4.2 [-] e_[CaI/Fe] [0.06/0.24] Total uncertainty in [CaI/Fe]
161- 162 I2 --- nTiI [1/19]? Number of TiI LTE lines used
164- 167 F4.2 [-] loge(TiI) [1.21/4.21]? Log epsilon mean abundance of
TiI
169- 173 F5.2 [-] [TiI/Fe] [-0.35/1.16]? TiI abundance relative to FeI
175- 178 F4.2 [-] e_[TiI/Fe] [0.05/0.52]? Total uncertainty in [TiI/Fe]
180- 181 I2 --- nTiII [2/34] Number of TiII LTE lines used
183- 186 F4.2 [-] loge(TiII) [1.31/4.4] Log epsilon mean abundance of
TiII
188- 192 F5.2 [-] [TiII/Fe] [-0.14/1.04] TiII abundance relative to FeI
194- 197 F4.2 [-] e_[TiII/Fe] [0.09/0.32] Total uncertainty in [TiII/Fe]
199- 200 I2 --- nCrI [1/13] Number of CrI LTE lines used
202- 205 F4.2 [-] loge(CrI) [1.03/4.53] Log epsilon mean abundance of
CrI
207- 211 F5.2 [-] [CrI/Fe] [-0.67/0.3] CrI abundance relative to FeI
213- 216 F4.2 [-] e_[CrI/Fe] [0.06/0.4] Total uncertainty in [CrI/Fe]
218 I1 --- nCrII [1/4]? Number of CrII LTE lines used
220- 223 F4.2 [-] loge(CrII) [2.1/4.73]? Log epsilon mean abundance of
CrII
225- 229 F5.2 [-] [CrII/Fe] [-0.39/0.58]? CrII abundance relative to
FeI
231- 234 F4.2 [-] e_[CrII/Fe] [0.15/0.65]? Total uncertainty in [CrII/Fe]
236- 237 I2 --- nNiI [1/18]? Number of NiI LTE lines used
239- 242 F4.2 [-] loge(NiI) [2.03/5.24]? Log epsilon mean abundance of
NiI
244- 248 F5.2 [-] [NiI/Fe] [-0.34/0.49]? NiI abundance relative to FeI
250- 253 F4.2 [-] e_[NiI/Fe] [0.06/0.41]? Total uncertainty in [NiI/Fe]
255 I1 --- nZnI [1/3]? Number of ZnI LTE lines used
257- 260 F4.2 [-] loge(ZnI) [1.28/3.81]? Log epsilon mean abundance of
ZnI
262- 266 F5.2 [-] [ZnI/Fe] [-0.55/1.04]? ZnI abundance relative to FeI
268- 271 F4.2 [-] e_[ZnI/Fe] [0.1/0.54]? Total uncertainty in [ZnI/Fe]
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Note (1): Abundances derived from O I, Na I, Mg I, Si I, K I, Fe I, and
Fe II lines have been corrected for NLTE. Their LTE abundances
are presented in this Table for reference, but we recommend
adopting the NLTE-corrected abundances presented in Table 5.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Stellar identifier
14- 15 I2 --- nFeI-NLTE [7/32] Number of FeI NLTE lines used
(1)
17- 20 F4.2 [-] loge(FeI)-NLTE [3.56/6.5] Log epsilon mean abundance
of FeI
22- 26 F5.2 [-] [FeI/H]-NLTE [-3.94/-1.0] FeI abundance relative to
H
28- 31 F4.2 [-] e_[FeI/H]-NLTE [0.06/0.18] Total uncertainty in
[FeI/H]-NLTE
33- 34 I2 --- nFeII-NLTE [1/13]? Number of FeII NLTE lines used
(1)
36- 39 F4.2 [-] loge(FeII)-NLTE [3.42/6.5]? Log epsilon mean abundance
of FeII
41- 45 F5.2 [-] [FeII/H]-NLTE [-4.08/-1.0]? FeII abundance relative
to H
47- 50 F4.2 [-] e_[FeII/H]-NLTE [0.13/0.6]? Total uncertainty in
[FeII/H]-NLTE
52 I1 --- nOI-NLTE [1/4]? Number of OI NLTE lines used (1)
54- 57 F4.2 [-] loge(OI)-NLTE [6.55/8.72]? Log epsilon mean
abundance of OI
59- 62 F4.2 [-] [OI/Fe]-NLTE [0.1/2.85]? OI abundance relative to
FeI
64- 67 F4.2 [-] e_[OI/Fe]-NLTE [0.13/0.33]? Total uncertainty in
[OI/Fe]-NLTE
69 I1 --- nNaI-NLTE [1/4]? Number of NaI NLTE lines used
(1)
71- 74 F4.2 [-] loge(NaI)-NLTE [2.38/5.22]? Log epsilon mean
abundance of NaI
76- 80 F5.2 [-] [NaI/Fe]-NLTE [-0.63/1.53]? NaI abundance relative
to FeI
82- 85 F4.2 [-] e_[NaI/Fe]-NLTE [0.16/0.31]? Total uncertainty in
[NaI/Fe]-NLTE
87 I1 --- nMgI-NLTE [1/9] Number of MgI NLTE lines used (1)
89- 92 F4.2 [-] loge(MgI)-NLTE [4.02/7.18] Log epsilon mean abundance
of MgI
94- 98 F5.2 [-] [MgI/Fe]-NLTE [-0.36/1.58] MgI abundance relative to
FeI
100- 103 F4.2 [-] e_[MgI/Fe]-NLTE [0.1/0.26] Total uncertainty in
[MgI/Fe]-NLTE
105 I1 --- nSiI-NLTE [1/4]? Number of SiI NLTE lines used
(1)
107- 110 F4.2 [-] loge(SiI)-NLTE [3.63/6.86]? Log epsilon mean
abundance of SiI
112- 116 F5.2 [-] [SiI/Fe]-NLTE [-0.29/1.14]? SiI abundance relative
to FeI
118- 121 F4.2 [-] e_[SiI/Fe]-NLTE [0.13/0.56]? Total uncertainty in
[SiI/Fe]-NLTE
123 I1 --- nKI-NLTE [1/2]? Number of KI NLTE lines used (1)
125- 128 F4.2 [-] loge(KI)-NLTE [1.43/4.21]? Log epsilon mean
abundance of KI
130- 138 A9 [-] [KI/Fe]-NLTE ? KI abundance relative to FeI
140- 143 F4.2 [-] e_[KI/Fe]-NLTE [0.17/0.26]? Total uncertainty in
[KI/Fe]-NLTE
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Note (1): The number of lines listed in the Table refers to the number of
lines for which NLTE corrections were calculated. These corrections
have been added to the LTE abundances for individual lines to
recompute the NLTE abundances listed here using the procedure
explained in Section 4.3. For O I, Na I, Mg I, Si I, K I, Fe I,
and Fe II, we recommend adopting the NLTE-corrected abundances
presented here.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Robin Leichtnam [CDS] 05-Jan-2026