J/A+A/493/913 Abundances of 9 HB stars in NGC 6352 (Feltzing+, 2009)
Stellar abundances and ages for metal-rich Milky Way globular clusters.
Stellar parameters and elemental abundances for 9 HB stars in NGC 6352.
Feltzing S., Primas F., Johnson R.A.
<Astron. Astrophys. 493, 913 (2009)>
=2009A&A...493..913F 2009A&A...493..913F
ADC_Keywords: Clusters, globular ; Stars, horizontal branch ; Abundances
Keywords: Galaxy: globular clusters: individual: NGC 6352 -
stars: horizontal-branch - stars: abundances
Abstract:
Metal-rich globular clusters provide important tracers of the
formation of our Galaxy. Moreover, and not less important, they are
very important calibrators for the derivation of properties of
extra-galactic metal-rich stellar populations. Nonetheless, only a few
of the metal-rich globular clusters in the Milky Way have been studied
using high-resolution stellar spectra to derive elemental abundances.
Additionally, Rosenberg et al. identified a small group of metal-rich
globular clusters that appeared to be about 2 billion years younger
than the bulk of the Milky Way globular clusters. However, it is
unclear if like is compared with like in this dataset as we do not
know the enhancement of alpha-elements in the clusters and the amount
of alpha-elements is well known to influence the derivation of ages
for globular clusters. We present a study of elemental abundances for
alpha and iron-peak elements for nine HB stars in the metal-rich
globular cluster NGC 6352. The elemental abundances are based on
high-resolution, high signal-to-noise spectra obtained with the UVES
spectrograph on VLT. The elemental abundances have been derived using
standard LTE calculations and stellar parameters have been derived
from the spectra themselves by requiring ionizational as well as
excitational equilibrium. We find that NGC 6352 has [Fe/H]=-0.55, is
enhanced in the alpha-elements to about +0.2dex for Ca, Si, and Ti
relative to Fe. For the iron-peak elements we find solar values. Based
on the spectroscopically derived stellar parameters we find that an
E(B-V)=0.24 and (m-M).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 61 9 Data for our sample
abun.dat 26 143 Elemental abundances for the nine stars in NGC 6352
ew.dat 32 3222 Measured equivalent widths for 13 elements
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See also:
J/AJ/110/652 : VI photometry in NGC 6352 (Fullton+ 1995)
J/A+AS/129/237 : G and K dwarfs abundances (Feltzing+ 1998)
J/A+A/410/527 : Abundances in the Galactic disk (Bensby+, 2003)
J/A+A/415/155 : Oxygen abundances in the Galactic disk (Bensby+, 2004)
J/A+A/433/185 : Detailed abundance analysis of 102 F & G dwarfs (Bensby+ 2005)
J/A+A/467/665 : Manganese abundances in the Galactic disk (Feltzing+, 2007)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- --- [NGC 6352]
10- 11 I2 --- Seq [01/09] Star number, as in Fig. 1
13 A1 --- --- [A]
14- 16 I3 --- ALC ? Alcaino (1971A&A....11....7A 1971A&A....11....7A) number,
Cl* NGC 6352 ALC NNN in Simbad
18 A1 --- --- [H]
19- 21 I3 --- HH ? Hartwick & Hesser (1972ApJ...175...77H 1972ApJ...175...77H)
number, NGC 6352 NNN in Simbad
23- 32 F10.6 deg RAdeg Right ascension in decimal degrees (J2000) (1)
34- 43 F10.6 deg DEdeg Declination in decimal degrees (J2000) (1)
45- 49 F5.2 mag Vmag HST V555 magnitude
51- 54 F4.2 mag V-I HST V555-I814 colour index
56- 61 F6.3 mag Kmag 2MASS K magnitude
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Note (1): Positions from 2MASS (Skrutskie et al., 2006AJ....131.1163S 2006AJ....131.1163S).
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Byte-by-byte Description of file: abun.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [01/09]? Star number, as in Fi.g 1
3- 6 A4 --- n_Seq [Mean Med] Mean or Median abundance for all stars
8- 11 A4 --- El Element and ionizational stage
(I for neutral, II for singly ionized)
13- 17 F5.2 [Sun] Abund Abundance of the element
19- 22 F4.2 [Sun] sigma ? The associate line-to-line scatter (1)
24- 26 I3 --- NLine ? Number of lines used in the determination
of the abundance
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Note (1): Note that this is the line-to-line scatter. The error in the mean
for the abundance is hence sigma/sqrt(NLine).
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Byte-by-byte Description of file: ew.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [01/09] Star number, as in Fig. 1
4- 7 A4 --- El Element and ionizational stage
(I for neutral, II for singly ionized)
9- 15 F7.2 0.1nm Lambda Wavelength for the line, in Angstrom
17- 20 F4.2 eV Chi Excitation energy of the lower level
22- 26 F5.2 --- log(gf) Oscillator strengths used in the
abundance analysis
28- 32 F5.1 0.1pm EW Equivalenth widths
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Acknowledgements:
Sofia Feltzing, sofia(at)astro.lu.se
(End) Sofia Feltzing [Lund Obs., Sweden], Patricia Vannier [CDS] 23-Oct-2008