J/A+A/550/A34 Abundances of red giants in M4 and 47 Tuc (Carretta+, 2013)
An aluminium tool for multiple stellar generations in the globular clusters
47 Tucanae and M 4.
Carretta E., Gratton R.G., Bragaglia A., D'Orazi V., Lucatello S.
<Astron. Astrophys., 550, A34 (2013)>
=2013A&A...550A..34C 2013A&A...550A..34C
ADC_Keywords: Clusters, globular ; Stars, giant ; Abundances
Keywords: stars: abundances - stars: atmospheres - stars: population II -
globular clusters: individual: 47 Tucanae -
globular clusters: general - globular clusters: individual: M4
Abstract:
We present aluminium abundances for a sample of about 100 red giant
stars in each of the Galactic globular clusters 47 Tuc (NGC 104) and
M 4 (NGC 6121). We have derived homogeneous abundances from
intermediate-resolution FLAMES/GIRAFFE spectra. Aluminium abundances
are from the strong doublet AlI 8772-8773Å, as in previous works
done for giants in NGC 6752 and NGC 1851, and nitrogen abundances are
extracted from a large number of features of the CN molecules by
assuming a suitable carbon abundance. We added previous homogeneous
abundances of O and Na and newly derived abundances of Mg and Si for
our samples of 83 stars in M 4 and 116 stars in 47 Tuc to obtain the
full set of elements from proton-capture reactions produced by
different stellar generations in these clusters.
Description:
The present work is based on two exposures, the first of 2700s at
airmass 1.487 (seeing=1.23") acquired on 2010, July 30 for 47 Tuc and
the second of 1600s at airmass 1.240 (seeing=1.79") taken on 2010,
April 14 with FLAMES@VLT-UT2 and the high-resolution grating HR21. The
resolution is 17300 at the center of the spectra, and the spectral
range goes from about 8484 to about 9001Å, including the AlI
doublet at 8772-73Å, which is the main feature we were interested
in.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 59 147 Derived abundances in 47 Tuc (table6 in html version)
table3.dat 59 103 Derived abundances in M 4 (table7 in html version)
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See also:
J/A+A/505/117 : Abundances of red giants in 15 globular clusters
(Carretta+, 2009)
J/A+A/435/657 : Equivalent widths of 5 giants in 47 Tuc (Alves-Brito+, 2005)
J/AJ/135/1551 : Abundances of stars in 47 Tuc (Koch+, 2008)
J/A+A/490/625 : Abundances of NGC 6121 red giants (Marino+, 2008)
J/ApJ/689/1031 : Heavy element abundances in giant stars (Yong+, 2008)
J/ApJ/716/L166 : Lithium abundances in red giants of M4 (D'Orazi+, 2010)
J/MNRAS/412/81 : Lithium abundance in M4 red giants (Mucciarelli+, 2011)
Byte-by-byte Description of file: table2.dat table3.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- Star Star number (1)
8- 9 I2 --- nr ? Number of CN features used to derive [N/Fe]
11- 14 F4.2 [Sun] [N/Fe] ? [N/Fe] abundance
16- 19 F4.2 [Sun] e_[N/Fe] ? rms uncertainty on [N/Fe]
21- 24 F4.2 [Sun] [Al/Fe] ? [Al/Fe] abundance
26- 29 F4.2 [Sun] e_[Al/Fe] ? Errors in the abundance of Al due to
errors in flux
31- 34 I4 --- S/N ? Signal-to-noise ratio
36 I1 --- nMg Number of Mg lines
38- 41 F4.2 [Sun] [Mg/Fe] Abundance [Mg/Fe]
43- 46 F4.2 [Sun] e_[Mg/Fe] ? rms uncertainty on [Mg/Fe]
48- 49 I2 --- nSi Number of Si lines
51- 54 F4.2 [Sun] [Si/Fe] Abundance [Si/Fe]
56- 59 F4.2 [Sun] e_[Si/Fe] ? rms uncertainty on [Si/Fe]
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Note (1): Star identified as <[CBG2009] NGC 104 NNNNNN> (47 Tuc) and
<[CBG2009] NGC 6121 NNNNNN> (M 4) in Simbad.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 29-Apr-2013