J/ApJ/717/277 Chemical composition of old LMC clusters (Mucciarelli+, 2010)
Chemical composition of the old globular clusters NGC 1786, NGC 2210, and
NGC 2257 in the Large Magellanic Cloud.
Mucciarelli A., Origlia L., Ferraro F.R.
<Astrophys. J., 717, 277-288 (2010)>
=2010ApJ...717..277M 2010ApJ...717..277M
ADC_Keywords: Abundances ; Stars, giant ; Radial velocities ; Magellanic Clouds
Spectroscopy ; Clusters, globular ; Abundances, [Fe/H]
Keywords: globular clusters: general - Magellanic Clouds - stars: abundances -
techniques: spectroscopic
Abstract:
This paper presents the chemical abundance analysis of a sample of
18 giant stars in three old globular clusters in the Large Magellanic
Cloud (LMC), NGC 1786, NGC 2210, and NGC 2257. The derived iron
content is [Fe/H]=-1.75±0.01dex (σ=0.02dex), -1.65±0.02dex
(σ=0.04dex), and -1.95±0.02dex (σ=0.04dex) for NGC 1786,
NGC 2210, and NGC 2257, respectively. All the clusters exhibit similar
abundance ratios, with enhanced values (~+0.30dex) of [α/Fe],
consistent with the Galactic halo stars, thus indicating that these
clusters have formed from a gas enriched by Type II supernovae. We
also found evidence that r-process is the main channel of production
of the measured neutron capture elements (Y, Ba, La, Nd, Ce, and Eu).
In particular, the quite large enhancement of [Eu/Fe] (~+0.70dex)
found in these old clusters clearly indicates a relevant efficiency of
the r-process mechanism in the LMC environment.
Description:
The observations were carried out with the multi-object spectrograph
FLAMES at the UT2/Kuyeen ESO-VLT (2007 December 25-27).
File Summary:
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FileID Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 65 19 Information about the target stars
table2.dat 53 19 Atmospherical parameters and derived [Fe/H] ratio
table3.dat 91 19 [O/Fe], [Na/Fe], [Mg/Fe], [Al/Fe], [Si/Fe], and
[Ca/Fe] abundance ratios
table4.dat 79 19 [Ti/Fe], [Sc/Fe]II, [V/Fe], [Cr/Fe], and [Ni/Fe]
abundance ratios
table5.dat 91 19 [Y/Fe]II, [Ba/Fe]II, [La/Fe]II, [Ce/Fe]II,
[Nd/Fe]II, and [Eu/Fe]II abundance ratios
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See also:
VII/183 : The Cluster System of the LMC (Kontizas+ 1990)
J/ApJ/695/L134 : Chemical anomalies in three old LMC clusters (Mucciarelli+,
2009)
J/AJ/136/375 : Chemical composition of LMC red giants (Mucciarelli+, 2008)
J/AJ/132/1630 : CaII spectroscopy in Magellanic Cloud clusters (Grocholski+,
2006)
J/ApJ/611/270 : Magellanic star clusters IR fluctuations (Gonzalez+, 2004)
J/A+A/404/187 : Equivalent widths for metal-poor stars (Gratton+, 2003)
J/AJ/98/2086 : CCD photometry of NGC 2257 RR Lyrae (Walker 1989)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [NGC]
5- 13 A9 --- ID Giant star name (NNNN-NNNN)
15- 23 A9 --- S/N ? Signal/Noise ratio (1)
25- 29 F5.1 km/s HRV ? Heliocentric velocity
31- 35 F5.2 mag K0mag ? Dereddened K0-band magnitude
37- 40 F4.2 mag (J-K)0 ? Dereddeded J-K color index
42- 51 F10.7 deg RAdeg ? Right ascension in decimal degrees onto
2MASS astrometric system (J2000)
53- 63 F11.7 deg DEdeg ? Declination in decimal degrees onto 2MASS
astrometric system (J2000)
65 A1 --- Inst [UG]? Adopted instrumental configuration
(U for UVES and G for GIRAFFE spectra)
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Note (1): Computed at 6000Å for the UVES spectra and at 5720 and 6260Å
for the GIRAFFE-HR11 and GIRAFFE-HR13 spectra, respectively.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [NGC]
5- 13 A9 --- ID Giant star name (NNNN-NNNN)
15- 18 I4 K Teff ? Spectroscopic effective temperature
20- 23 I4 K Teffp ? Photometric effective temperature
25- 28 F4.2 [cm/s2] logg ? Surface gravity
30- 34 F5.2 [-] [A/H] ? Metallicity
36- 39 F4.2 km/s Vt ? Microturbulent velocity
41- 42 I2 --- N ? Number of used lines
44- 48 F5.2 [Sun] [Fe/H] ? Fe/H metallicity (1)
50- 53 F4.2 [Sun] e_[Fe/H] ? Fe/H internal error (2)
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Note (1): Solar value for Fe is 7.54dex (Gratton et al. 2003,
Cat. J/A+A/404/187).
Note (2): Associated internal error defined as σ/Nlines0.5
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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- 3 A3 --- --- [NGC ]
5- 13 A9 --- ID Star identification (NNNN-NNNN)
15 I1 --- NO ? Number of line(s) used for [O/Fe]
17 A1 --- l_[O/Fe] Limit flag in [O/Fe]
18- 22 F5.2 [-] [O/Fe] O/Fe abundance ratio
24- 27 F4.2 [-] e_[O/Fe] ? [O/Fe] internal error
29 I1 --- NNa ? Number of line(s) used for [Na/Fe]
31- 35 F5.2 [-] [Na/Fe] Na/Fe abundance ratio
37- 40 F4.2 [-] e_[Na/Fe] ? [Na/Fe] internal error
42 I1 --- NMg ? Number of line(s) used for [Mg/Fe]
44- 48 F5.2 [-] [Mg/Fe] Mg/Fe abundance ratio
50- 53 F4.2 [-] e_[Mg/Fe] ? [Mg/Fe] internal error
55 I1 --- NAl ? Number of line(s) used for [Al/Fe]
57 A1 --- l_[Al/Fe] Limit flag in [Al/Fe]
58- 61 F4.2 [-] [Al/Fe] ? Al/Fe abundance ratio
63- 66 F4.2 [-] e_[Al/Fe] ? [Al/Fe] internal error
68 I1 --- NSi ? Number of line(s) used for [Si/Fe]
70- 73 F4.2 [-] [Si/Fe] Si/Fe abundance ratio
75- 78 F4.2 [-] e_[Si/Fe] ? [Si/Fe] internal error
80- 81 I2 --- NCa ? Number of line(s) used for [Ca/Fe]
83- 86 F4.2 [-] [Ca/Fe] Ca/Fe abundance ratio
88- 91 F4.2 [-] e_[Ca/Fe] ? [Ca/Fe] internal error
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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- 3 A3 --- --- [NGC ]
5- 13 A9 --- ID Star identification (NNNN-NNNN)
15- 16 I2 --- NTi ? Number of line(s) used for [Ti/Fe]
18- 21 F4.2 [-] [Ti/Fe] ? Ti/Fe abundance ratio
23- 26 F4.2 [-] e_[Ti/Fe] ? [Ti/Fe] internal error
28 I1 --- NSc ? Number of line(s) used for [Sc/Fe]
30- 34 F5.2 [-] [Sc/Fe]II Abundance ratio of [Sc/Fe]II
36- 39 F4.2 [-] e_[Sc/Fe]II ? [Sc/Fe]II internal error
41 I1 --- NV ? Number of line(s) used for [V/Fe]
43- 47 F5.2 [-] [V/Fe] ? V/Fe abundance ratio
49- 52 F4.2 [-] e_[V/Fe] ? [V/Fe] internal error
54 I1 --- NCr ? Number of line(s) used for [Cr/Fe]
56- 60 F5.2 [-] [Cr/Fe] ? Cr/Fe abundance ratio
62- 65 F4.2 [-] e_[Cr/Fe] ? [Cr/Fe] internal error
67- 68 I2 --- NNi ? Number of line(s) used for [Ni/Fe]
70- 74 F5.2 [-] [Ni/Fe] Ni/Fe abundance ratio
76- 79 F4.2 [-] e_[Ni/Fe] ? [Ni/Fe] internal error
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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- 3 A3 --- --- [NGC ]
5- 13 A9 --- ID Star identification (NNNN-NNNN)
15 I1 --- NY ? Number of line(s) used for [Y/Fe]II
17- 21 F5.2 [-] [Y/Fe]II ? Abundance ratio of [Y/Fe]II
23- 26 F4.2 [-] e_[Y/Fe]II ? [Y/Fe]II internal error
28 I1 --- NBa ? Number of line(s) used for [Ba/Fe]II
30- 34 F5.2 [-] [Ba/Fe]II Abundance ratio of [Ba/Fe]II
36- 39 F4.2 [-] e_[Ba/Fe]II ? [Ba/Fe]II internal error
41 I1 --- NLa ? Number of line(s) used for [La/Fe]II
43 A1 --- l_[La/Fe]II Limit flag in [La/Fe]II
44- 48 F5.2 [-] [La/Fe]II ? Abundance ratio of [La/Fe]II
50- 53 F4.2 [-] e_[La/Fe]II ? [La/Fe]II internal error
55 I1 --- NCe ? Number of line(s) used for [Ce/Fe]
57 A1 --- l_[Ce/Fe]II Limit flag in [Ce/Fe]II
58- 62 F5.2 [-] [Ce/Fe]II ? Abundance ratio of [Ce/Fe]II
64- 67 F4.2 [-] e_[Ce/Fe]II ? [Ce/Fe]II internal error
69 I1 --- NNd ? Number of line(s) used for [Nd/Fe]II
71- 74 F4.2 [-] [Nd/Fe]II ? Abundance ratio of [Nd/Fe]II
76- 79 F4.2 [-] e_[Nd/Fe]II ? [Nd/Fe]II internal error
81 I1 --- NEu ? Number of line(s) used for [Eu/Fe]II
83- 86 F4.2 [-] [Eu/Fe]II ? Abundance ratio of [Eu/Fe]II
88- 91 F4.2 [-] e_[Eu/Fe]II ? [Eu/Fe]II internal error
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Nomenclature notes:
Stars are <[MOF2009] NGC NNNN NNNN> in Simbad.
History:
From electronic version of the journal
References:
Ferraro et al. Iron Content of NGC 1978 in the LMC.
2006ApJ...645L..33F 2006ApJ...645L..33F
Mucciarelli et al. Chemical composition of LMC red giants.
2008AJ....136..375M 2008AJ....136..375M Cat. J/AJ/136/375
Mucciarelli et al. Chemical anomalies in three old LMC clusters.
2009ApJ...695L.134M 2009ApJ...695L.134M Cat. J/ApJ/695/L134
(End) Emmanuelle Perret [CDS] 27-Apr-2011