J/A+A/565/A23 Abundances of NGC5897 red giants (Koch+, 2014)
The chemical composition of a regular halo globular cluster: NGC 5897.
Koch A., McWilliam A.
<Astron. Astrophys. 565, A23 (2014)>
=2014A&A...565A..23K 2014A&A...565A..23K
ADC_Keywords: Galaxies, nearby ; Stars, giant ; Abundances
Keywords: stars: abundances - Galaxy: abundances - Galaxy: evolution -
globular clusters: individual: NGC 5897 - Galaxy: halo
Abstract:
We report for the first time on the chemical composition of the halo
cluster NGC 5897 (R☉=12.5kpc), based on chemical abundance
ratios for 27 α-, iron-peak, and neutron-capture elements in
seven red giants. From our high-resolution, high signal-to-noise
spectra obtained with theMagellan/MIKE spectrograph, we find a mean
iron abundance from the neutral species of
[Fe/H]=-2.04±0.01(stat.)±0.15(sys.), which is more metal-poor
than implied by previous photometric and low-resolution spectroscopic
studies. NGC 5897 is α-enhanced (to 0.34±0.01dex) and shows
Fe-peak element ratios typical of other (metal-poor) halo globular
clusters (GCs) with no overall, significant abundance spreads in iron
nor in any other heavy element.
Description:
Our observations were performed with the Magellan Inamori Kyocera
Echelle (MIKE) spectrograph at the 6.5-m Magellan2/Clay Telescope at
Las Campanas Observatory, Chile. The data were gathered over four
nights in May 2013.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 86 8 Properties of the targeted stars
table2.dat 88 301 Line list for the seven studied giants
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Name Identifications from Sandage & Katem
(1968ApJ...153..569S 1968ApJ...153..569S), S-NNN,
in Simbad
6 A1 --- n_Name [d] d: Variable star V5 (Sandage & Katem
1968ApJ...153..569S 1968ApJ...153..569S)
7- 14 A8 --- OName ID from Testa et al. (2001AJ....121..916T 2001AJ....121..916T),
ESO-NNNN
15 A1 --- n_OName [e] e: Non-member
17- 18 I2 h RAh Right ascension (J2000)
20- 21 I2 min RAm Right ascension (J2000)
23- 27 F5.2 s RAs Right ascension (J2000)
29 A1 --- DE- Declination sign (J2000)
30- 31 I2 deg DEd Declination (J2000)
33- 34 I2 arcmin DEm Declination (J2000)
36- 40 F5.2 arcsec DEs Declination (J2000)
42- 46 F5.2 mag Vmag V magnitude
48- 51 F4.2 mag V-I V-I colour index
53- 56 F4.2 mag V-K V-K colour index
58- 68 A11 "date" Date Date of observation
69 A1 --- --- [,]
70- 71 I2 --- n_Date ? Second day of observation
73- 76 I4 s Texp Exposure time
78- 80 I3 --- S/N Signa-to-noise ratio measured in the order
containing Hα
82- 86 F5.1 km/s HV Heliocentric velocity
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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- 4 F4.1 --- Ion Ion designation
8- 14 F7.2 0.1nm lambda Wavelength λ
19- 22 F4.2 eV EP Excitation potential
26- 32 F7.3 [-] loggf Oscillator strength
38- 40 I3 10-13m EW255 ? Equivalent width for S-255 (mÅ)
46- 48 I3 10-13m EW20 ? Equivalent width for S-20 (mÅ)
54- 56 I3 10-13m EW9 ? Equivalent width for S-9 (mÅ)
62- 64 I3 10-13m EW366 ? Equivalent width for S-366 (mÅ)
70- 72 I3 10-13m EW138 ? Equivalent width for S-138 (mÅ)
78- 80 I3 10-13m EW290 ? Equivalent width for S-290 (mÅ)
86- 88 I3 10-13m EW364 ? Equivalent width for S-364 (mÅ)
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Acknowledgements:
Andreas Koch, akoch(at)lsw.uni-heidelberg.de
(End) Patricia Vannier [CDS] 11-Mar-2014