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J/A+A/465/815       Abundances of Sgr dSph stars             (Sbordone+, 2007)

The exotic chemical composition of the Sagittarius dwarf spheroidal galaxy. Sbordone L., Bonifacio P., Buonanno R., Marconi G., Monaco L., Zaggia S. <Astron. Astrophys., 465, 815-824 (2007)> =2007A&A...465..815S
ADC_Keywords: Abundances, [Fe/H] ; Equivalent widths ; Clusters, globular ; Stars, giant Keywords: stars: abundances - stars: atmospheres - galaxies: abundances - galaxies: dwarf - galaxies: individual: Sgr dSph - globular clusters: individual: Terzan 7 Abstract: The Sagittarius dwarf spheroidal galaxy is the nearest neighbor of the Milky Way. Moving along a short period quasi-polar orbit within the Halo, it is being destroyed by the tidal interaction with our Galaxy, losing its stellar content along a huge stellar stream. We study the detailed chemical composition of 12 giant stars in the Sagittarius dwarf Spheroidal main body, together with 5 more in the associated globular cluster Terzan 7, by means of high resolution VLT-UVES spectra. Abundances are derived for up to 21 elements from O to Nd, by fitting lines EW or line profiles against ATLAS 9 model atmospheres and SYNTHE spectral syntheses calculated ad-hoc. Temperatures are derived from (V-I)0 or (B-V)0 colors and gravities from FeI-FeII ionization equilibrium. The metallicity of the observed stars is between [Fe/H]=-0.9 and 0. We detected a highly peculiar "chemical signature", with undersolar alpha elements, Na, Al , Sc, V, Co, Ni, Cu, and Zn, among others, and overabundant La, Ce, and Nd. Many of these abundance ratios (in particular light-odd elements and iron peak ones) are strongly at odds with what is observed within the Milky Way, so they may be a very useful tool for recognizing populations originating within the Sagittarius dwarf. This can be clearly seen in the case of the globular Palomar 12, which is believed to have been stripped from Sagittarius: the cluster shows precisely the same chemical "oddities", thus finally confirming its extragalactic origin. Description: Tables A1-A3 of the paper detailing wavelengths, loggf, reference for the atomic data, measured equivalent widths and derived abundances for the 12 Sgr dSph stars and the 5 Ter 7 stars in the paper. Objects: --------------------------------------------------------- RA (2000) DE Designation(s) --------------------------------------------------------- 18 55 03.1 -30 28 42 Sgr dSph = NAME SGR DWARF GALAXY 19 17 43.7 -34 39 27 Ter7 = Cl Terzan 7 --------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 41 17 Photometry and atmospheric parameters for the studied stars tablea.dat 41 2083 Equivalent widths and abundances refs.dat 119 25 References
See also: J/A+A/414/503 : Abundances in the Sgr dSph (Bonifacio+, 2004) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 4 A4 --- Parent Sgr or Ter7 6- 9 I4 --- Star Star number (G1) 11- 16 F6.3 mag Vmag V magnitude 18- 22 F5.3 mag (V-I)0 ? Dereddened V-I colour index (Sgr stars only) 24- 28 F5.3 mag (B-V)0 ? Dereddened B-V colour index (Ter7 stars only) 29- 32 I4 K Teff Effective temperature 34- 36 F3.1 [cm/s2] logg Surface gravity 38- 41 F4.2 km/s xi Turbulent velocity
Byte-by-byte Description of file: tablea.dat
Bytes Format Units Label Explanations
1- 4 I4 --- Star Star number (G1) 6- 9 A4 --- Ion Ion name 11- 18 F8.4 nm Lambda Line laboratory wavelength (2) 20- 25 F6.3 --- loggf line oscillator strength 27- 30 A4 --- r_loggf References for employed loggf 32- 36 F5.2 pm EW ?=0.0 Equivalent width (3) 38- 41 F4.2 --- Abund ?=0.0 Abundance
Note (2): Where HFS has been taken into account, the wavelength is provided with 0.01nm precision only, for the feature is actually not a single line. Note (3): All "real" values are above 1.0pm here. -- A value of 0.01 indicates that the abundance has been derived by fitting agains a synthetic spectrum due to line blending. -- A value of 0.02 indicates synthetic spectrum fitting taking into account HFS. -- A value of 0.0 indicates the line has not been measured for this star. In this case the abundance is also put to 0.0.
Byte-by-byte Description of file: refs.dat
Bytes Format Units Label Explanations
1- 4 A4 --- Ref Reference code 6- 24 A19 --- BibCode BibCode 26- 45 A20 --- Aut Author's name 49-119 A71 --- Com Comments
Blobal notes: Note (G1): Nomenclature: Stars 439 to 927 are Sgr dSph stars, [MBC98a] Sgr1 NNN in Simbad. Stars 1272 to 1708 are Terzan 7 stars, Cl* Terzan 7 BCP NNNN in Simbad.
Acknowledgements: Luca Sbordone, luca.sbordone(at)obspm.fr References: Bonifacio et al., Paper I 2000A&A...359..663B Sbordone et al., Paper II 2005A&A...437..905S Bonifacio et al., Paper III 2004A&A...414..503B, Cat. J/A+A/414/503
(End) Patricia Vannier [CDS] 12-Apr-2007
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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