J/ApJ/927/13 Metal-poor stars observed with SALT/HRS. II. (Zepeda+, 2022)
Metal-poor stars observed with the Southern African Large Telescope
II. An Extended Sample.
Zepeda J., Rasmussen K.C., Beers T.C., Placco V.M., Huang Y., Depagne E.
<Astrophys. J., 927, 13 (2022)>
=2022ApJ...927...13Z 2022ApJ...927...13Z
ADC_Keywords: Radial velocities; Abundances; Effective temperatures;
Stars, metal-deficient; Spectra, optical
Keywords: Milky Way stellar halo ; Stellar abundances ; Stellar atmospheres ;
CEMP stars ; R-process ; Population II stars
Abstract:
We present results from high-resolution (R∼40000) spectroscopic
observations of over 200 metal-poor stars, mostly selected from the
RAVE survey, using the Southern African Large Telescope. We were able
to derive stellar parameters for a total of 108 stars; an additional
sample of 50 stars from this same effort was previously reported on by
Rasmussen+ 2020ApJ...905...20R 2020ApJ...905...20R (Cat. J/ApJ/905/20). Among our newly
reported observations, we identify 84 very metal-poor (VMP;
[Fe/H]<-2.0, 53 newly identified) stars and three extremely
metal-poor (EMP; [Fe/H]<-3.0, one newly identified) stars. The
elemental abundances were measured for carbon, as well as several
other α-elements (Mg, Ca, Sc, and Ti), iron-peak elements (Mn,
Co, Ni, and Zn), and neutron-capture elements (Sr, Ba, and Eu). Based
on these measurements, the stars are classified by their carbon and
neutron-capture abundances into carbon-enhanced metal-poor (CEMP;
[C/Fe]>+0.70), CEMP subclasses, and by the level of their r-process
abundances. A total of 17 are classified as CEMP stars. There are
11 CEMP-r stars (eight newly identified), one CEMP-s star (newly
identified), two possible CEMP-i stars (one newly identified), and
three CEMP-no stars (all newly identified) in this work. We found
11 stars (eight newly identified) that are strongly enhanced in
r-process elements (r-II; [Eu/Fe]>+0.70), 38 stars (31 newly
identified) that are moderately enhanced in r-process elements (r-I;
+0.30<[Eu/Fe]≤+0.70), and one newly identified limited-r star.
Description:
A total of 223 high-resolution (R∼40000) spectroscopic observations of
the relatively bright targets were completed with the Southern African
Large Telescope (SALT) High-Resolution Spectrograph (HRS; 3970-5560Å)
from 2017 April to 2019 April. The total observation time was 55h.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 66 107 Position, date of observation, and radial velocity
table3.dat 103 107 Signal-to-noise and stellar parameters
table4.dat 27 396 Line list for equivalent-width analysis
table5.dat 115 107 Abundances of alpha elements
table6.dat 135 107 Abundances of Iron-Peak Elements
table7.dat 128 107 Classifications, Carbon, and neutron-capture elements
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See also:
III/279 : RAVE 5th data release (Kunder+, 2017)
III/283 : RAVE 6th data release (Steinmetz+, 2020)
J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992)
J/AJ/130/2804 : Carbon abundances in metal-poor stars (Rossi+, 2005)
J/ApJ/655/492 : Equivalent widths of 26 metal-poor stars (Aoki+, 2007)
J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)
J/MNRAS/412/843 : SAGA extremely metal-poor stars (Suda+, 2011)
J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013)
J/ApJ/794/58 : Metal-poor stars in the thick disk of the Gal. (Beers+, 2014)
J/A+A/571/A47 : Extensive linelist of CH in stellar atm. (Masseron+, 2014)
J/ApJ/797/21 : Carbon-enhanced metal-poor stars (Placco+, 2014)
J/ApJS/211/5 : Line data for the Swan system 12C13C (Ram+, 2014)
J/ApJS/214/26 : Line lists for CN isotopes transitions (Sneden+, 2014)
J/ApJ/807/171 : SkyMapper Survey metal-poor star spectrosc. (Jacobson+, 2015)
J/AJ/151/82 : 4 brightest red giants in UFD galaxy Ret 2 (Roederer+, 2016)
J/ApJ/833/20 : Carbon-enhanced metal-poor (CEMP) star abund. (Yoon+, 2016)
J/ApJ/835/81 : Bright metal-poor stars from HES Survey. II. (Beers+, 2017)
J/ApJ/838/44 : Abundances of the brightest member of Tuc III (Hansen+, 2017)
J/ApJ/858/92 : RPA Southern Pilot Search of 107 Stars (Hansen+, 2018)
J/AJ/155/256 : Sp. validation of RAVE metal-poor stars (Placco+, 2018)
J/AJ/156/179 : r-process-enhanced field stars kinematics (Roederer+, 2018)
J/ApJ/868/110 : R-Process Alliance: 1st release in Gal. halo (Sakari+, 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/ApJS/249/30 : R-Process Alliance: metal-poor star sp. (Holmbeck+, 2020)
J/ApJ/905/20 : Metal-poor stars observed with SALT/HRS (Rasmussen+, 2020)
J/A+A/649/A49 : Spectroscopic study of CEMP-(s & r/s) stars (Goswami+, 2021)
J/ApJ/908/79 : The r-process Alliance; abund. in 519 stars (Gudin+, 2021)
J/AJ/162/229 : 13 Magellanic Clouds metal-poor stars (Reggiani+, 2021)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Identifier
25- 33 F9.4 deg RAdeg Right Ascension (J2000)
35- 42 F8.4 deg DEdeg [-75.3/13.1] Declination (J2000)
44- 47 I4 yr Obs.Y [2017/2019] Year of the observation
49- 51 A3 "month" Obs.M Month of the observation
53- 54 I2 d Obs.D Day of the observation
56- 61 F6.1 km/s RVel [-320.7/452] Radial velocity
63- 66 F4.1 km/s e_RVel [0/12.4] Uncertainty in RVel
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Identifier
25- 59 A35 --- OName Other name
61- 63 I3 --- SNR [21/150] Signal-to-Noise ratio at 5033Å
65- 68 I4 K Teff [4420/6281] Effective temperature
70- 72 I3 K e_Teff [150] Uncertainty in Teff
74- 77 F4.2 [cm/s2] log(g) [0.6/4.3] log surface gravity
79- 82 F4.2 [cm/s2] e_log(g) [0.3] Uncertainty in log(g)
84- 87 F4.2 km/s xi [0.9/4] Microturbulent velocity
89- 92 F4.2 km/s e_xi [0.2] Uncertainty in xi
94- 98 F5.2 [Sun] [Fe/H] [-3.24/-0.76] Metallicity
100-103 F4.2 [Sun] e_[Fe/H] [0.06/0.3] Uncertainty in [Fe/H]
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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- 5 A5 --- Ion Ion identifier
7- 14 F8.3 0.1nm lambda [3908.7/5573.1] Wavelength; Angstroms
16- 20 F5.3 eV chi [0/4.6] Excitation potential
22- 27 F6.3 [-] log(gf) [-5.7/0.56] log oscillator strength
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Identifier
25- 29 F5.2 [Sun] [Mg/Fe] [-0.34/0.78] Log magnesium-to-iron ratio
31- 34 F4.2 [Sun] e_[Mg/Fe] [0.1/0.8] Uncertainty in [Mg/Fe]
36- 36 I1 --- o_[Mg/Fe] [1/8] Number of lines used to determine [Mg/Fe]
38- 42 F5.2 [Sun] [Si/Fe] [0.06/1.7]? log silicon-to-iron ratio
44- 47 F4.2 [Sun] e_[Si/Fe] [0.2]? Uncertainty in [Si/Fe]
49- 49 I1 --- o_[Si/Fe] [1]? Number of lines used to determine [Si/Fe]
51- 55 F5.2 [Sun] [Ca/Fe] [-0.42/0.91] Log calcium-to-iron ratio
57- 60 F4.2 [Sun] e_[Ca/Fe] [0.1/0.6] Uncertainty in [Ca/Fe]
62- 63 I2 --- o_[Ca/Fe] [1/11] Number of lines used to
determine [Ca/Fe]
65- 69 F5.2 [Sun] [Sc/Fe] [-0.25/0.63] Log scandium-to-iron ratio
71- 74 F4.2 [Sun] e_[Sc/Fe] [0.1/0.6] Uncertainty in [Sc/Fe]
76- 76 I1 --- o_[Sc/Fe] [1/9] Number of lines used to determine [Sc/Fe]
78- 82 F5.2 [Sun] [Ti/Fe] [0.1/0.9] Log titanium-to-iron ratio
84- 87 F4.2 [Sun] e_[Ti/Fe] [0.09/0.3] Uncertainty in [Ti/Fe]
89- 90 I2 --- o_[Ti/Fe] [19/84] Number of lines used to
determine [Ti/Fe]
92- 95 F4.2 [-] log(Mg) [4.9/7] log magnesium number abundance
97-100 F4.2 [-] log(Si) [5.16/7.02]? log silicon number abundance
102-105 F4.2 [-] log(Ca) [3.48/5.91] log calcium number abundance
107-110 F4.2 [-] log(Sc) [0.02/3.02] log scandium number abundance
112-115 F4.2 [-] log(Ti) [2/5] log titanium number abundance
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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- 23 A23 --- Name Identifier
25- 29 F5.2 [Sun] [Cr/Fe] [-0.5/0.23]? Log chromium-to-iron ratio
31- 34 F4.2 [Sun] e_[Cr/Fe] [0.06/0.34]? Uncertainty in [Cr/Fe]
36- 37 I2 --- o_[Cr/Fe] [4/25]? Number of lines used to
determine [Cr/Fe]
39- 43 F5.2 [Sun] [Mn/Fe] [-0.84/0.34]? log manganese-to-iron ratio
45- 48 F4.2 [Sun] e_[Mn/Fe] [0.1/0.71]? Uncertainty in [Mn/Fe]
50- 50 I1 --- o_[Mn/Fe] [1/7]? Number of lines used to determine [Mn/Fe]
52- 56 F5.2 [Sun] [Co/Fe] [-0.73/1.1]? Log cobalt-to-iron ratio
58- 61 F4.2 [Sun] e_[Co/Fe] [0.1/0.6]? Uncertainty in [Co/Fe]
63- 63 I1 --- o_[Co/Fe] [1/5]? Number of lines used to determine [Co/Fe]
65- 69 F5.2 [Sun] [Fe/H] [-3.24/-0.76] Log Fe/H abundance
71- 74 F4.2 [Sun] e_[Fe/H] [0.06/0.24] Uncertainty in [Fe/H]
76- 78 I3 --- o_[Fe/H] [36/152] Number of lines used to
determine [Fe/H]
80- 84 F5.2 [Sun] [Ni/Fe] [-0.13/0.24] Log nickel-to-iron ratio
86- 89 F4.2 [Sun] e_[Ni/Fe] [0.1/0.62] Uncertainty in [Ni/Fe]
91- 92 I2 --- o_[Ni/Fe] [1/17] Number of lines used to determine [Ni/Fe]
94- 98 F5.2 [Sun] [Zn/Fe] [-0.07/0.62]? Log zinc-to-iron ratio
100-103 F4.2 [Sun] e_[Zn/Fe] [0.1/1]? Uncertainty in [Zn/Fe]
105-105 I1 --- o_[Zn/Fe] [0/2]? Number of lines used to determine [Zn/Fe]
107-110 F4.2 [-] log(Cr) [2/5.11]? log chromium number abundance
112-115 F4.2 [-] log(Mn) [1.69/4.82]? log manganese number abundance
117-120 F4.2 [-] log(Co) [2/5]? log cobalt number abundance
122-125 F4.2 [-] log(Fe) [3.7/6.74] log iron number abundance
127-130 F4.2 [-] log(Ni) [2/5.63] log nickel number abundance
132-135 F4.2 [-] log(Zn) [0/4.11]? log zinc number abundance
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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- 23 A23 --- Name Identifier
25- 31 A7 --- Class Classification
33- 37 F5.2 [Sun] [C/Fe] [-1.15/1.16] Log carbon-to-iron ratio
39- 42 F4.2 [Sun] e_[C/Fe] [0.3/0.3] Uncertainty in [C/Fe]
44- 44 I1 --- o_[C/Fe] [1] Number of lines used to determine [C/Fe]
46- 50 F5.2 [Sun] [C/Fe]c [-1.15/1.17]? Log corrected carbon-to-iron
ratio (1)
52- 55 F4.2 [Sun] e_[C/Fe]c [0.3]? Uncertainty in [C/Fe]c(1)
57- 60 F4.2 --- ACc [5.5/7.7]? Corrected carbon number abundance (1)
62- 66 F5.2 [Sun] [Sr/Fe] [-1.02/0.68]? Log strontium-to-iron ratio
68- 71 F4.2 [Sun] e_[Sr/Fe] [0.1/0.6]? Uncertainty in [Sr/Fe]
73- 73 I1 --- o_[Sr/Fe] [0/2]? Number of lines used to determine [Sr/Fe]
75- 79 F5.2 [Sun] [Ba/Fe] [-1.32/1.55] Log barium-to-iron ratio
81- 84 F4.2 [Sun] e_[Ba/Fe] [0.2] Uncertainty in [Ba/Fe]
86- 86 I1 --- o_[Ba/Fe] [1/2] Number of lines used to determine [Ba/Fe]
88- 92 F5.2 [Sun] [Eu/Fe] [-0.21/1.7]? Log europium-to-iron ratio
94- 97 F4.2 [Sun] e_[Eu/Fe] [0.2]? Uncertainty in [Eu/Fe]
99- 99 I1 --- o_[Eu/Fe] [1/3]? Number of lines used to determine [Eu/Fe]
101-105 F5.2 [Sun] [Ba/Eu] [-1.9/0.81]? Log barium-to-europium ratio
107-110 F4.2 [Sun] e_[Ba/Eu] [0.28]? Uncertainty in [Ba/Eu]
112-116 F5.2 [-] log(Sr) [-0.71/2.25]? log strontium number abundance
118-122 F5.2 [-] log(Ba) [-2.15/1.71] log barium number abundance
124-128 F5.2 [-] log(Eu) [-2.26/0.15]? log europium number abundance
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Note (1): Corrected for evolutionary effects.
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History:
From electronic version of the journal
References:
Rasmussen et al. Paper I. 2020ApJ...905...20R 2020ApJ...905...20R Cat. J/ApJ/905/20
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 10-Nov-2023