J/ApJ/712/L21 Calcium abundances in 17 globular clusters (Carretta+, 2010)
Calcium and light-elements abundance variations from high-resolution
spectroscopy in globular clusters.
Carretta E., Bragaglia A., Gratton R., Lucatello S., Bellazzini M.,
D'Orazi V.
<Astrophys. J., 712, L21-L25 (2010)>
=2010ApJ...712L..21C 2010ApJ...712L..21C
ADC_Keywords: Abundances ; Clusters, globular ; Stars, giant
Keywords: globular clusters: general - stars: abundances - stars: evolution
Abstract:
We use abundances of Ca, O, Na, and Al from high-resolution UVES
spectra of 200 red giants in 17 globular clusters (GCs) to investigate
the correlation found by Lee et al. (2009Icar..199..413C 2009Icar..199..413C) between
chemical enrichment from SNII and star-to-star variations in light
elements in GC stars. We find that (1) the [Ca/H] variations between
first and second generation stars are tiny in most GCs (∼0.02-0.03dex,
comparable with typical observational errors). In addition, (2) using
a large sample of red giants in M4 (NGC 6121) with abundances from
UVES spectra from Marino et al. (2008, Cat. J/A+A/490/625), we find
that Ca and Fe abundances in the two populations of Na-poor and
Na-rich stars are identical.
Description:
The full description of the analysis is given in Carretta et al.
(2009, Cat. J/A+A/505/139); here we present only the abundances of Ca,
which are based on a large number of lines (typically 10-12 in the
most metal-poor clusters like M15 (NGC 7078) and almost 20 in
metal-rich GCs like 47 Tuc (NGC 104)).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 40 202 The [Ca/Fe] and [Ca/H] ratios for individual stars
table2.dat 43 17 Mean [Ca/Fe], [Ca/H] ratios and internal errors
for the 17 globular clusters
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See also:
J/A+A/505/139 : Abundances of red giants in 17 globular clusters (Carretta+,
2009)
J/A+A/503/545 : Equivalent widths of Li, Na, Fe, Ca in NGC 6397 (Lind+, 2009)
J/A+A/490/625 : Abundances of NGC 6121 red giants (Marino+, 2008)
J/A+A/490/777 : Abundances of Population II stars in NGC 6397 (Lind+, 2008)
J/A+A/486/941 : Abundances in M71 (NGC 6838) (Alves-Brito+, 2008)
J/A+A/464/939 : Abundances of red giants in NGC 6218 (Carretta+, 2007)
J/A+A/464/927 : Abundances of red giants in NGC 6752 (Carretta+, 2007)
J/AJ/131/1766 : Abundances and equivalent widths in NGC 2808 (Carretta, 2006)
J/A+A/434/235 : Abundances of BHB stars in NGC 1904 (Fabbian+, 2005)
J/A+A/440/901 : Reddening and metallicity of NGC 6752 (Gratton, 2005)
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]
4- 7 I4 --- NGC NGC number of the globular cluster
9- 15 I7 --- ID Star identification (1)
17- 18 I2 --- NCa Number of Ca lines
20- 25 F6.3 [Sun] [Ca/Fe] The [Ca/Fe] abundance ratio
27- 31 F5.3 [Sun] e_[Ca/Fe] The rms error in Ca/Fe
33- 38 F6.3 [Sun] [Ca/H] The [Ca/H] abundance ratio
40 I1 --- PIE [0,3] PIE flag (2)
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Note (1): Stars are <[CBG2009] NGC NNNN NNNNNNN> in Simbad.
Note (2): 1, 2, and 3 for the primordial P, intermediate I and extreme E
component, respectively; 0 means that either Na or O was missing and
the star could be not assigned to a component.
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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- 3 A3 --- --- [NGC]
5- 8 I4 --- NGC NGC number of the globular cluster
10- 11 I2 --- N Number of stars studied in the cluster
13- 17 F5.2 [Sun] [Ca/Fe] The [Ca/Fe] abundance ratio
19- 22 F4.2 [Sun] e_[Ca/Fe] The rms error in [Ca/Fe]
24- 27 F4.2 [Sun] err1 Error 1 (1)
29- 32 F4.2 [Sun] err2 Error 2 (1)
34- 38 F5.2 [Sun] [Ca/H] The [Ca/H] abundance ratio
40- 43 F4.2 [Sun] e_[Ca/H] The rms error in [Ca/H]
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Note (1): err1 for [Ca/Fe] accounts for internal errors in Teff, vt,
and EW, whereas err2 includes all sources of uncertainties (see
Carretta et al. 2009, Cat. J/A+A/505/139).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 11-Apr-2012