J/ApJ/834/105 High-resolution GC abundances. II. (Colucci+, 2017)
Globular cluster abundances from high-resolution, integrated-light spectroscopy.
II. Expanding the metallicity range for old clusters and updated analysis
techniques.
Colucci J.E., Bernstein R.A., McWilliam A.
<Astrophys. J., 834, 105-105 (2017)>
=2017ApJ...834..105C 2017ApJ...834..105C (SIMBAD/NED BibCode)
ADC_Keywords: Abundances ; Clusters, globular ; Spectroscopy ; Equivalent widths
Keywords: galaxies: abundances; galaxies: star clusters: general;
globular clusters: general
Abstract:
We present abundances of globular clusters (GCs) in the Milky Way and
Fornax from integrated-light (IL) spectra. Our goal is to evaluate the
consistency of the IL analysis relative to standard abundance analysis
for individual stars in those same clusters. This sample includes an
updated analysis of seven clusters from our previous publications and
results for five new clusters that expand the metallicity range over
which our technique has been tested. We find that the [Fe/H] measured
from IL spectra agrees to ∼0.1dex for GCs with metallicities as high
as [Fe/H]=-0.3, but the abundances measured for more metal-rich
clusters may be underestimated. In addition we systematically evaluate
the accuracy of abundance ratios, [X/Fe], for Na I, Mg I, Al I, Si I,
Ca I, Ti I, Ti II, Sc II, V I, Cr I, Mn I, Co I, Ni I, Cu I, Y II, Zr
I, Ba II, La II, Nd II, and Eu II. The elements for which the IL
analysis gives results that are most similar to analysis of individual
stellar spectra are Fe I, Ca I, Si I, Ni I, and Ba II. The elements
that show the greatest differences include Mg I and Zr I. Some
elements show good agreement only over a limited range in metallicity.
More stellar abundance data in these clusters would enable more
complete evaluation of the IL results for other important elements.
Description:
The observations and reductions of the original training set sample
are described in detail in Paper I (McWilliam & Bernstein,
2008ApJ...684..326M 2008ApJ...684..326M) and Cameron (2009PhDT........20C 2009PhDT........20C). The data were
obtained using the echelle spectrograph on the 2.5m du Pont telescope
at Las Campanas. The spectra cover the range 3700-7800Å. All
clusters, excluding NGC 2808, were observed during lunar dark time in
2000 July. NGC 2808 was observed during lunar dark time in 2001
January. The total integration time for each cluster is summarized in
Table 1, along with the general properties of the clusters.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 89 12 Observations and cluster properties
table3.dat 60 214 Globular cluster (GC) Fe I equivalent-widths (EWs)
table4.dat 32 106 Fe I synthesis abundances
table5.dat 81 21 Synthesized Fe II abundances
table6.dat 66 12 Final results for Fe abundance and derived ages
table9.dat 88 199 Individual line abundances
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See also:
J/A+A/578/A116 : Abundances of red giant stars in NGC6093 (Carretta+, 2015)
J/A+A/572/A108 : 47 Tuc red giants chemical composition (Thygesen+, 2014)
J/AJ/148/67 : Abundances of 156 bulge red giants (Johnson+, 2014)
J/A+A/567/A72 : Stellar parameters & abundances in NGC6752 (Gruyters+, 2014)
J/A+A/565/A8 : Stroemgren photometry near NGC 6528 (Calamida+, 2014)
J/MNRAS/437/1609 : NGC 2808 HB stars abundances (Marino+, 2014)
J/ApJ/780/94 : Abundances of red giants in 47 Tuc (Cordero+, 2014)
J/MNRAS/434/358 : 4 Galactic globular clusters Fe line depths (Sakari+, 2013)
J/A+A/557/A138 : Detailed chemical abundances in NGC 362 (Carretta+ 2013)
J/ApJ/771/67 : Abundances for 97 metal-poor stars. II. (Ishigaki+, 2013)
J/ApJ/749/175 : Abundances for stars in Plaut's window (Johnson+, 2012)
J/ApJ/746/29 : High-resolution GC abundances. IV. 8 LMC GCs (Colucci+, 2012)
J/A+A/534/A123 : Horizontal branch stars in NGC 2808 (Gratton+, 2011)
J/AJ/142/63 : Abundance of five stars in NGC 6397 (Koch+, 2011)
J/ApJ/735/55 : High-resolution GCs abundances. III. LMC (Colucci+, 2011)
J/A+A/530/A54 : Abundances of 650 bulge red giants (Gonzalez+, 2011)
J/A+A/527/A148 : NGC6397 red giants chemical composition (Lind+, 2011)
J/A+A/513/A35 : Abundances of Galactic red giants (Alves-Brito+, 2010)
J/AJ/135/1551 : Abundances of stars in 47 Tuc (Koch+, 2008)
J/A+A/464/967 : Abundances of red giants in NGC 6388 (Carretta+, 2007)
J/A+A/455/271 : Abundances of red giants in NGC 6441 (Gratton+, 2006)
J/AJ/131/1766 : Abundances and equivalent widths in NGC 2808 (Carretta, 2006)
J/ApJS/161/304 : Star clusters in the MW and satellites (McLaughlin+, 2005)
J/AJ/130/2140 : Abundances & velocities in globular clusters (Pritzl+, 2005)
J/MNRAS/340/304 : [X/Fe] of Galactic disc F and G dwarfs (Reddy+, 2003)
J/A+A/385/67 : HST VI photom. & proper motions in NGC 6528 (Feltzing+, 2002)
J/AJ/120/1841 : Abundances & Kinematics of Halo & Disk Stars (Fulbright 2000)
J/A+A/303/468 : Spectrospcopy, IR-photom. in GCs (Minniti, 1995)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- f_Name [zn] Flag on Name (1)
3- 10 A8 --- Name Globular cluster name
12- 13 I2 h RAh Hour of right ascension (J2000) (2)
15- 16 I2 min RAm Minute of right ascension (J2000)
18- 21 F4.1 s RAs Second of right ascension (J2000)
23 A1 --- DE- Sign of declination (J2000) (2)
24- 25 I2 deg DEd Degree of declination (J2000) (2)
27- 28 I2 arcmin DEm Arcminute of declination (J2000)
30- 33 F4.1 arcsec DEs Arcsecond of declination (J2000)
35- 39 F5.2 mag/arcsec muV Milky Way central surface brightnesses
in V from McLaughlin & van der Marel
(2005, J/ApJS/161/304)
40 A1 --- f_muV [a] a: from Harris (1991ARA&A..29..543H 1991ARA&A..29..543H,
2010 revision)
42- 46 F5.2 mag Vmag [3.9/12.6] V-band magnitude (2)
48- 52 F5.2 mag VMag [-9.7/-6.5] Total V-band absolute magnitude
(MVtot)
54- 57 F4.2 mag E(B-V) [0.04/1.1] Color excess (2)
59- 62 F4.2 arcmin Rcore [0.04/3.2] Core radius (2)
64- 71 A8 --- Tel Telescope
73- 79 A7 --- Area Scan area
81- 85 I5 s Exp [2700/25200] Exposure time
87- 89 I3 /pix S/N [52/200] Signal-to-noise ratio in pixel-1
--------------------------------------------------------------------------------
Note (1): Flag as follows:
z = New Clusters from Zaritsky et al. (2014ApJ...796...71Z 2014ApJ...796...71Z)
n = new Fornax Cluster. Coordinates and core radius for Fornax 3 are from
Mackey & Gilmore (2003MNRAS.340..175M 2003MNRAS.340..175M).
The E(B-V) and VMag for Fornax 3 are from Buonanno+ (1998ApJ...501L..33B 1998ApJ...501L..33B),
using their distance modulus of 20.68.
Note (2): Milky Way cluster identifications, positions, V magnitudes, E(B-V),
and core radius in arcminutes are from Harris (1991ARA&A..29..543H 1991ARA&A..29..543H,
2010 revision; see also VII/202).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.2 0.1nm lambda [4114.4/7568.9] Wavelength; in Angstroms (1)
9- 12 F4.2 eV ExPot [0/5] Excitation potential
14- 18 F5.2 [-] log(gf) [-6.4/0.7] Log of the oscillator strength
20- 24 F5.1 10-13m EW3 [25.6/143.2]? Equivalent width of Fornax 3 (2)
26- 30 F5.1 10-13m EW104 [12/147.4]? Equivalent width of NGC 104 (2)
32- 36 F5.1 10-13m EW2808 [27.5/186.3]? Equivalent width of NGC 2808 (2)
38- 42 F5.1 10-13m EW362 [34.8/149.6]? Equivalent width of NGC 362 (2)
44- 48 F5.1 10-13m EW6093 [38.5/141.7]? Equivalent width of NGC 6093 (2)
50- 54 F5.1 10-13m EW6397 [14.9/116.6]? Equivalent width of NGC 6397 (2)
56- 60 F5.1 10-13m EW6752 [23/129.8]? Equivalent width of NGC 6752 (2)
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Note (1): Lines listed twice correspond to measurements made in adjacent orders
with overlapping spectral coverage.
Note (2): In units of milli-Angstroms.
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.2 0.1nm lambda [4114.4/7583.8] Wavelength; in Angstroms
9- 12 F4.2 [-] N6388 [6.6/7.5]? 12+log(X/H) FeI Abundance
for NGC 6388 (1)
14- 17 F4.2 [-] N6440 [6.6/7.5]? 12+log(X/H) FeI Abundance
for NGC 6440 (1)
19- 22 F4.2 [-] N6441 [6.4/7.4]? 12+log(X/H) FeI Abundance
for NGC 6441 (1)
24- 27 F4.2 [-] N6528 [6.6/7.6]? 12+log(X/H) FeI Abundance
for NGC 6528 (1)
29- 32 F4.2 [-] N6553 [6.6/7.5]? 12+log(X/H) FeI Abundance
for NGC 6553 (1)
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Note (1): Abundance measurements from χ2 fitting of spectral syntheses
for NGC 6388, NGC 6440, NGC 6441, NGC 6528 and NGC 6553. Abundances
for individual lines are measured in steps of 0.1 dex from the mean
abundance obtained from all lines. Abundances are quoted for the CMD
solution with the oldest age for each GC.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Species Species
9- 15 F7.2 0.1nm lambda [4122.6/6516.1] Wavelength; in Angstroms
17- 20 F4.2 eV ExPot [2.5/3.9] Excitation potential
22- 26 F5.2 [-] log(gf) [-4.8/-1.1] Log of the oscillator strength
28- 31 F4.2 [-] F3 [5.3/5.7]? 12+log(X/H) FeII Abundance
for Fornax 3 (1)
33- 36 F4.2 [-] N104 [6.5/7.1]? 12+log(X/H) FeII Abundance
for NGC 104 (1)
38- 41 F4.2 [-] N2808 [6.4/7]? 12+log(X/H) FeII Abundance
for NGC 2808 (1)
43- 46 F4.2 [-] N362 [6/6.6]? 12+log(X/H) FeII Abundance
for NGC 362 (1)
48- 51 F4.2 [-] N6093 [5.4/6.1]? 12+log(X/H) FeII Abundance
for NGC 6093 (1)
53- 56 F4.2 [-] N6388 [6.98]? 12+log(X/H) FeII Abundance
for NGC 6388 (1)
58- 61 F4.2 [-] N6440 [7.1/7.3]? 12+log(X/H) FeII Abundance
for NGC 6440 (1)
63- 66 F4.2 [-] N6441 [6.7/7.6]? 12+log(X/H) FeII Abundance
for NGC 6441 (1)
68- 71 F4.2 [-] N6528 [6.6/7.8]? 12+log(X/H) FeII Abundance
for NGC 6528 (1)
73- 76 F4.2 [-] N6553 [6.7/7.5]? 12+log(X/H) FeII Abundance
for NGC 6553 (1)
78- 81 F4.2 [-] N6752 [5.6/6.2]? 12+log(X/H) FeII Abundance
for NGC 6752 (1)
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Note (1): Abundance measurements from χ^2 fitting of spectral syntheses
Abundances for individual lines are measured in steps of 0.1dex from
the mean abundance obtained from all lines. Abundances are quoted for
the CMD solution with the oldest age for each GC.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Name Cluster name
10- 14 F5.2 --- [FeI/H] [-2.3/-0.3] mean abundance from FeI lines
16- 19 F4.2 --- SigFeI [0.1/0.3] Standard deviation σ (1)
21- 24 F4.2 --- s_[FeI/H] [0.02/0.2] Uncertainty in abundance
σA,FeI (2)
26- 29 F4.2 --- e_[FeI/H] [0.03/0.2] Total uncertainty σFeI (3)
31- 33 I3 --- NFeI [36/111] Number of FeI lines
35- 39 F5.2 --- [FeII/H] [-2.2/-0.2]? mean abundance from FeII lines
41- 44 F4.2 --- SigFeII [0.1/0.4]? Standard deviation σ (1)
46- 49 F4.2 --- s_[FeII/H] [0.01/0.06]? Uncertainty in abundance
σA,FeII (2)
51- 54 F4.2 --- e_[FeII/H] [0.03/0.3]? Total uncertainty σFeII (3)
56- 57 I2 --- NFeII [1/15]? Number of FeII lines
59- 62 F4.1 Gyr Age [8.5/14] Age
64- 66 F3.1 Gyr e_Age [1/6] Age uncertainty
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Note (1): Standard deviation in the abundance measured from the lines of
each species.
Note (2): the uncertainty in abundance due to the age range of the best
solutions, σA,X
Note (3): the total uncertainty for each species, which is defined as
σX=(σA,X2+σN,X2)0.5,
where σN,X=σ/(NX-1)0.5 and σ is the standard
deviation of the abundance of NX lines.
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Species Species
9- 15 F7.2 0.1nm lambda [4061/7932.4] Wavelength; in Angstroms
17- 20 F4.2 eV ExPot [0/6] Excitation potential
22- 26 F5.2 [-] log(gf) [-5.6/0.6] Log of the oscillator strength
28- 31 F4.2 [-] Sun [0.4/7.7] 12+log(X/H) Species Abundance
for the Sun (1)
33- 37 F5.2 [-] F3 [-1/5.5]? 12+log(X/H) Species Abundance
for Fornax 3
39- 42 F4.2 [-] N104 [0.1/7.7]? 12+log(X/H) Species Abundance
for NGC 104
44- 47 F4.2 [-] N2808 [0.6/7]? 12+log(X/H) Species Abundance
for NGC 2808
49- 53 F5.2 [-] N362 [-0.3/7]? 12+log(X/H) Species Abundance
for NGC 362
55- 58 F4.2 [-] N6093 [0.1/6.4]? 12+log(X/H) Species Abundance
for NGC 6093
60- 63 F4.2 [-] N6388 [1.7/7.7]? 12+log(X/H) Species Abundance
for NGC 6388
65- 68 F4.2 [-] N6440 [0.7/8]? 12+log(X/H) Species Abundance
for NGC 6440
70- 73 F4.2 [-] N6441 [0.7/7.6]? 12+log(X/H) Species Abundance
for NGC 6441
75- 78 F4.2 [-] N6528 [1/7.7]? 12+log(X/H) Species Abundance
for NGC 6528
80- 83 F4.2 [-] N6553 [0.5/7.6]? 12+log(X/H) Species Abundance
for NGC 6553
85- 88 F4.2 [-] N6752 [0.3/6.6]? 12+log(X/H) Species Abundance
for NGC 6752
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Note (1): The reference solar abundance for each line is given in "Sun",
see text for details.
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History:
From electronic version of the journal
References:
McWilliam & Bernstein. Paper I. 2008ApJ...684..326M 2008ApJ...684..326M
Colucci et al. M31 2009ApJ...704..385C 2009ApJ...704..385C Cat. J/ApJ/704/385
Colucci et al. Paper III. 2011ApJ...735...55C 2011ApJ...735...55C Cat. J/ApJ/735/55
Colucci et al. Paper IV. 2012ApJ...746...29C 2012ApJ...746...29C Cat. J/ApJ/746/29
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 12-Jun-2017