J/ApJ/722/1373 ω Centauri giants abundances (Johnson+, 2010)
Chemical abundances for 855 giants in the globular cluster omega Centauri
(NGC 5139).
Johnson C.I., Pilachowski C.A.
<Astrophys. J., 722, 1373-1410 (2010)>
=2010ApJ...722.1373J 2010ApJ...722.1373J
ADC_Keywords: Abundances ; Equivalent widths ; Stars, giant ; Clusters, globular
Keywords: globular clusters: general - globular clusters: individual
(Omega Centauri) - stars: abundances - stars: Population II
Abstract:
We present elemental abundances for 855 red giant branch (RGB) stars
in the globular cluster Omega Centauri (ω Cen) from spectra
obtained with the Blanco 4m telescope and Hydra multifiber
spectrograph. The sample includes nearly all RGB stars brighter than
V=13.5 and spans ω Cen's full metallicity range. The heavy
α elements (Si, Ca, and Ti) are generally enhanced by ±0.3 dex
and exhibit a metallicity-dependent morphology that may be attributed
to mass and metallicity-dependent Type II supernova (SN) yields. The
heavy α and Fe-peak abundances suggest minimal contributions
from Type Ia SNe. The light elements (O, Na, and Al) exhibit >0.5 dex
abundance dispersions at all metallicities, and a majority of stars
with [Fe/H]>-1.6 have [O/Fe], [Na/Fe], and [Al/Fe] abundances similar
to those in monometallic globular clusters, as well as O-Na, O-Al
anticorrelations and the Na-Al correlation in all but the most
metal-rich stars. A combination of pollution from intermediate-mass
asymptotic giant branch stars and in situ mixing may explain the light
element abundance patterns. A large fraction (27%) of ω Cen
stars are O-poor ([O/Fe]<0) and are preferentially located within
5'-10' of the cluster center. The O-poor giants are spatially similar,
located in the same metallicity range, and are present in nearly equal
proportions to blue main-sequence stars. This suggests that the O-poor
giants and blue main-sequence stars may share a common origin. [La/Fe]
increases sharply at [Fe/H]≳-1.6, and the [La/Eu] ratios indicate
that the increase is due to almost pure s-process production.
Description:
The observations for this project were taken at the Cerro Tololo
Inter-American Observatory (CTIO) using the Blanco 4m telescope
equipped with the Hydra multifiber positioner and bench spectrograph.
We obtained all of the spectra in two separate runs spanning 2008
March 24-28 and 2009 March 6-8. We employed two different wavelength
setups encompassing ∼6135-6365 and ∼6500-6800Å with wavelength
centers near 6250 and 6670Å, respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 75 855 Star identifiers, photometry, and atmospheric
parameters
table3.dat 59 855 Fe atomic parameters, equivalent widths, and
solar abundances (6151.62-6265.14Å)
table3b.dat 55 855 Fe atomic parameters, equivalent widths, and
solar abundances (6270.23-6247.56Å)
table4.dat 60 855 O-Eu atomic parameters, equivalent widths, and
solar abundances (6300.31-6305.66Å)
table4b.dat 58 855 O-Eu atomic parameters, equivalent widths, and
solar abundances (6245.62-6645.06Å)
table5.dat 105 855 Chemical abundance ratios
table6.dat 41 855 Chemical abundance measurement uncertainties
(FeI, FeII, Na, Al, Si)
table6b.dat 40 855 Chemical abundance measurement uncertainties
(Ca, ScI, ScII, Ti, Ni)
ion.dat 28 57 Wavelengths explanations for tables 3 to 4b
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See also:
J/A+A/534/A53 : EW of 18 subgiant of ω Cen (Pancino+, 2011)
J/A+A/527/A18 : EW of 6 subgiants of ω Cen (Pancino+, 2011)
J/A+A/519/L3 : Lithium content of ω Cen (Monaco+, 2010)
J/ApJ/698/2048 : Abundances of red giants in ω Cen (Johnson+, 2009)
J/MNRAS/399/195 : Blue and red spectra of ω Cen (Van Loon+, 2009)
J/ApJ/681/1505 : Abundances of red giants in ω Cen (Johnson+, 2008)
J/ApJ/667/911 : Abundances of ω Cen (Stanford+, 2007)
J/ApJ/640/L43 : Metallicities of RR Lyrae stars in Omega Cen (Sollima+, 2006)
J/ApJ/647/1075 : Age-metallicity relation of ω Cen (Stanford+, 2006)
J/AJ/119/1824 : Caby photometry of Ω Centauri (Rey+, 2000)
J/A+A/360/472 : Proper motions in omega Centauri (van Leeuwen+, 2000)
J/ApJ/462/241 : Ca abundance for Omega Cen red giants (Norris+ 1996)
J/ApJS/99/637 : Equivalent widths for 54 red giants (Norris+ 1995)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- LEID Van Leeuwen et al. identifier (G1) (1)
7- 10 I4 --- ROA ? Woolley (1966ROAn....2....1W 1966ROAn....2....1W) identifier
( in Simbad)
12- 17 F6.3 mag Vmag The V band magnitude
19- 23 F5.3 mag B-V The (B-V) color index
25- 30 F6.3 mag Jmag 2MASS J band magnitude
32- 37 F6.3 mag Hmag 2MASS H band magnitude
39- 44 F6.3 mag Kmag 2MASS KS band magnitude
46- 49 I4 K Teff Effective temperature
51- 54 F4.2 [cm/s2] log(g) Log of the surface gravity
56- 60 F5.2 [Sun] [Fe/H] Average [Fe/H] metallicity
62- 65 F4.2 km/s Vt Microturbulence velocity
68 A1 --- l_S/N-6250 Limit flag on S/N-6250
69- 71 I3 --- S/N-6250 Signal-to-noise at 6250 Angstroms
73- 75 I3 --- S/N-6650 ? Signal-to-noise at 6650 Angstroms
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Note (1): The possible carbon stars shown in Figures 1 and 3 are:
LEID 32059, 33062, 35250, 37199, 39105, 41071, 42044, 43199, 43368,
44126, 44262, 44361, 44484, and 52030.
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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- 5 I5 --- LEID Van Leeuwen et al. identifier (G1)
7- 9 I3 10-13m EW6151.62 ? Equivalent width of Fe I 6151.62 (mÅ)
11- 13 I3 10-13m EW6157.73 ? Equivalent width of Fe I 6157.73 (mÅ)
15- 16 I2 10-13m EW6165.36 ? Equivalent width of Fe I 6165.36 (mÅ)
18- 20 I3 10-13m EW6173.34 ? Equivalent width of Fe I 6173.34 (mÅ)
22- 24 I3 10-13m EW6180.20 ? Equivalent width of Fe I 6180.20 (mÅ)
26- 28 I3 10-13m EW6187.99 ? Equivalent width of Fe I 6187.99 (mÅ)
30- 32 I3 10-13m EW6200.32 ? Equivalent width of Fe I 6200.32 (mÅ)
34- 36 I3 10-13m EW6219.28 ? Equivalent width of Fe I 6219.28 (mÅ)
38- 39 I2 10-13m EW6226.74 ? Equivalent width of Fe I 6226.74 (mÅ)
41- 43 I3 10-13m EW6229.23 ? Equivalent width of Fe I 6229.23 (mÅ)
45- 47 I3 10-13m EW6232.64 ? Equivalent width of Fe I 6232.64 (mÅ)
49- 51 I3 10-13m EW6246.32 ? Equivalent width of Fe I 6246.32 (mÅ)
53- 55 I3 10-13m EW6252.56 ? Equivalent width of Fe I 6252.56 (mÅ)
57- 59 I3 10-13m EW6265.14 ? Equivalent width of Fe I 6265.14 (mÅ)
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Byte-by-byte Description of file: table3b.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- LEID Van Leeuwen et al. 2000 identifier (G1)
7- 9 I3 10-13m EW6270.23 ? Equivalent width of Fe I 6270.23 (mÅ)
11- 12 I2 10-13m EW6271.28 ? Equivalent width of Fe I 6271.28 (mÅ)
14- 15 I2 10-13m EW6290.97 ? Equivalent width of Fe I 6290.97 (mÅ)
17- 19 I3 10-13m EW6297.79 ? Equivalent width of Fe I 6297.79 (mÅ)
21- 23 I3 10-13m EW6301.50 ? Equivalent width of Fe I 6301.50 (mÅ)
25- 27 I3 10-13m EW6302.49 ? Equivalent width of Fe I 6302.49 (mÅ)
29- 30 I2 10-13m EW6311.50 ? Equivalent width of Fe I 6311.50 (mÅ)
32- 33 I2 10-13m EW6315.81 ? Equivalent width of Fe I 6315.81 (mÅ)
35- 37 I3 10-13m EW6322.69 ? Equivalent width of Fe I 6322.69 (mÅ)
39- 41 I3 10-13m EW6335.33 ? Equivalent width of Fe I 6335.33 (mÅ)
43- 45 I3 10-13m EW6336.83 ? Equivalent width of Fe I 6336.83 (mÅ)
47- 49 I3 10-13m EW6344.15 ? Equivalent width of Fe I 6344.15 (mÅ)
51- 52 I2 10-13m EW6149.24 ? Equivalent width of Fe II 6149.24 (mÅ)
54- 55 I2 10-13m EW6247.56 ? Equivalent width of Fe II 6247.56 (mÅ)
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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 I5 --- LEID Van Leeuwen et al. 2000 identifier (G1)
7- 9 A3 --- EW6300.31 [syn] determined via spectrum synthesis
instead of equivalent width measurements
11- 13 I3 10-13m EW6154.23 ? Equivalent width of Na I 6154.23 (mÅ)
15- 17 I3 10-13m EW6160.75 ? Equivalent width of Na I 6160.75 (mÅ)
19- 21 A3 --- EW6696.03 [syn] determined via spectrum synthesis
instead of equivalent width measurements
23- 25 A3 --- EW6698.67 [syn] determined via spectrum synthesis
instead of equivalent width measurements
27- 29 I3 10-13m EW6155.13 ? Equivalent width of Si I 6155.13 (mÅ)
31- 32 I2 10-13m EW6237.32 ? Equivalent width of Si I 6237.32 (mÅ)
34- 36 I3 10-13m EW6161.29 ? Equivalent width of Ca I 6161.29 (mÅ)
38- 40 I3 10-13m EW6162.18 ? Equivalent width of Ca I 6162.18 (mÅ)
42- 44 I3 10-13m EW6166.44 ? Equivalent width of Ca I 6166.44 (mÅ)
46- 48 I3 10-13m EW6169.04 ? Equivalent width of Ca I 6169.04 (mÅ)
50- 52 I3 10-13m EW6169.56 ? Equivalent width of Ca I 6169.56 (mÅ)
54- 56 I3 10-13m EW6210.67 ? Equivalent width of Sc I 6210.67 (mÅ)
58- 60 I3 10-13m EW6305.66 ? Equivalent width of Sc I 6305.66 (mÅ)
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Byte-by-byte Description of file: table4b.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- LEID Van Leeuwen et al. identifier (G1)
7- 9 I3 10-13m EW6245.62 ? Equivalent width of Sc II 6245.62 (mÅ)
11- 12 I2 10-13m EW6309.88 ? Equivalent width of Sc II 6309.88 (mÅ)
14- 15 I2 10-13m EW6146.23 ? Equivalent width of Ti I 6146.23 (mÅ)
17- 19 I3 10-13m EW6258.11 ? Equivalent width of Ti I 6258.11 (mÅ)
21- 23 I3 10-13m EW6261.10 ? Equivalent width of Ti I 6261.10 (mÅ)
25- 27 I3 10-13m EW6303.76 ? Equivalent width of Ti I 6303.76 (mÅ)
29- 31 I3 10-13m EW6312.24 ? Equivalent width of Ti I 6312.24 (mÅ)
33- 35 I3 10-13m EW6336.11 ? Equivalent width of Ti I 6336.11 (mÅ)
37- 38 I2 10-13m EW6175.37 ? Equivalent width of Ni I 6175.37 (mÅ)
40- 41 I2 10-13m EW6176.81 ? Equivalent width of Ni I 6176.81 (mÅ)
43- 44 I2 10-13m EW6177.25 ? Equivalent width of Ni I 6177.25 (mÅ)
46- 47 I2 10-13m EW6186.71 ? Equivalent width of Ni I 6186.71 (mÅ)
49- 51 I3 10-13m EW6327.60 ? Equivalent width of Ni I 6327.60 (mÅ)
53- 55 A3 --- EW6262.29 [syn] determined via spectrum synthesis
instead of equivalent width measurements
57- 58 I2 10-13m EW6645.06 ? Equivalent width of Eu II 6645.06 (mÅ)
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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- 5 I5 --- LEID Van Leeuwen et al. identifier (G1)
7- 10 I4 --- ROA ? Woolley (1966ROAn....2....1W 1966ROAn....2....1W) identifier
( for Simbad)
12- 16 F5.2 [Sun] [FeI/H] The [FeI/H] number abundance
18- 22 F5.2 [Sun] [FeII/H] ? The [FeII/H] number abundance
24- 28 F5.2 [Sun] <[Fe/H]> Averaged [Fe/H] number abundance
30- 34 F5.2 [Sun] [O/Fe] ? The [O/Fe] number abundance
36- 40 F5.2 [Sun] [Na/Fe] ? The [Na/Fe] number abundance
42- 46 F5.2 [Sun] [Al/Fe] ? The [Al/Fe] number abundance
48- 52 F5.2 [Sun] [Si/Fe] ? The [Si/Fe] number abundance
54- 58 F5.2 [Sun] [Ca/Fe] ? The [Ca/Fe] number abundance
60- 64 F5.2 [Sun] [ScI/Fe] ? The [ScI/Fe] number abundance
66- 70 F5.2 [Sun] [ScII/Fe] ? The [ScII/Fe] number abundance
72- 76 F5.2 [Sun] [Sc/Fe] ? Averaged [Sc/Fe] number abundance
78- 82 F5.2 [Sun] [Ti/Fe] ? The [Ti/Fe] number abundance
84- 88 F5.2 [Sun] [Ni/Fe] ? The [Ni/Fe] number abundance
89 A1 --- u_[Ni/Fe] Uncertainty flag on [Ni/Fe]
91- 95 F5.2 [Sun] [LaII/Fe] ? The [LaII/Fe] number abundance
97-101 F5.2 [Sun] [EuII/Fe] ? The [EuII/Fe] number abundance
103-105 A3 --- Code Abundance code (2)
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Note (2): Code as follows:
1 = [O/Fe] upper limit;
2 = [Na/Fe] upper limit;
3 = [Al/Fe] upper limit;
4 = [La/Fe] upper limit.
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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- 5 I5 --- LEID Van Leeuwen et al. identifier (G1)
7- 8 I2 --- NFeI Number of FeI lines measured
10- 13 F4.2 --- sigFeI The FeI σ/N-FeI1/2 value
15 I1 --- NFeII ? Number of FeII lines measured
17- 20 F4.2 --- sigFeII ? The FeII σ/N-FeI1/2 value
22 I1 --- NNa ? Number of Na lines measured
24- 27 F4.2 --- sigNa ? The Na σ/N-Na1/2 value
29 I1 --- NAl ? Number of Al lines measured
31- 34 F4.2 --- sigAl ? The Al σ/N-Al1/2 value
36 I1 --- NSi ? Number of Si lines measured
38- 41 F4.2 --- sigSi ? The Si σ/N-Si1/2 value
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Byte-by-byte Description of file: table6b.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- LEID Van Leeuwen et al. identifier (G1)
7 I1 --- NCa ? Number of Ca lines measured
9- 12 F4.2 --- sigCa ? The Ca σ/N-FeI1/2 value
14 I1 --- NScI ? Number of ScI lines measured
16- 19 F4.2 --- sigScI ? The ScI σ/N-FeI1/2 value
21 I1 --- NScII ? Number of Sc IIlines measured
23- 26 F4.2 --- sigScII ? The ScII σ/N-FeI1/2 value
28 I1 --- NTi ? Number of Tilines measured
30- 33 F4.2 --- sigTi ? The Ti σ/N-FeI1/2 value
35 I1 --- NNi ? Number of Ni lines measured
37- 40 F4.2 --- sigNi ? The Ni σ/N-FeI1/2 value
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Byte-by-byte Description of file: ion.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Ion Ion identification
6- 12 F7.2 0.1nm lambda Wavelength (in Angstroms)
14- 17 F4.2 eV EP Excitation potential
19- 23 F5.2 [-] log(gf) Log of the oscillator strength
25- 28 F4.2 [-] eps Abundance of element in Sun
[εSun = log(Ion/H)+12]
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Global Notes:
Note (G1): Photometry, coordinates, and membership probabilities for all stars
were taken from the proper motion study by van Leeuwen et al. (2000,
Cat. J/A+A/360/472; <Cl* NGC 5139 Leid NNNNN> for Simbad).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 12-Jul-2012