All Figures

$\begin{figure} \par\includegraphics[angle=-90,width=15cm,clip]{2905_f1.eps} \end{figure}$ Figure 1: Grotrian diagram of the Quintet system. The decays that give rise to the lines of multiplets 1, 6, 8 are indicated in grey. The partial Grotrian diagram of the quintet system, including the lines of astrophysical interest, was adapted from Atomic energy-level and Grotrian diagrams by Bashkin & Stoner (1978).
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f2.eps} \end{figure}$ Figure 2: Fit in the region of 670 nm of the star HD 25704 (black observed spectrum, grey fitted spectrum). The Fe I 675.0152 is in good agreement with the [Fe/H] utilized, so we fitted the whole range including the S I lines of Mult. 8 and the lines of other elements as well.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f3.eps} \end{figure}$ Figure 3: Fit in the region of Mult. 8 of the star HD 10607; black is the observed spectrum and grey the fit.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f4.eps} \end{figure}$ Figure 4: Fit in the region of Mult. 6 of the star HD 10607. The solid line is the observed spectrum after subtraction of telluric lines; dotted line is observed spectrum, grey is the fit.
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In the text

$\begin{figure} \par\includegraphics[width=7cm,height=5cm,clip]{2905_f5.eps} \end{figure}$ Figure 5: Fit of the 922.8 nm S I line in star BD +17 408. It may be appreciated that the synthetic spectrum provides a good fit to the wings of Paschen $\zeta$ , while not to the core. This is not surprising since our synthetic spectra are computed in LTE and the core of Paschen lines is predicted to be affected by NLTE effects (see for example Johnson & Kinglesmith 1965).
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In the text

$\begin{figure} \par\includegraphics[width=7cm,height=5cm,clip]{2905_f6.eps} \end{figure}$ Figure 6: Two spectra with parameters: $T_{\rm eff}=6016$ K, log g = 4.04, and [Fe/H] = -1.5, the G 126 -62 star parameters. The black one is the one we used to fit the sulphur abundance, while the grey one is built without the 922.9017 nm Paschen $\zeta$ .
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f7.eps} \end{figure}$ Figure 7: Microturbulence effect on sulphur lines; the synthetic spectra plotted have: $T_{\rm eff}=5810$ K, log g = 4.50, [Fe/H]=-1.0, which are the parameters of the star HD 205650. This star has been selected to show microturbulence effect, because its parameters fall near the average of our sample.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f8.eps} \end{figure}$ Figure 8: Left: [S/H] derived from the lines of Mult. 6 versus [S/H] derived from the lines of Mult. 8 for all the stars with measurements in both multiplets. Right: [S/H] derived from the lines of Mult. 1 versus mean [S/H] derived from the lines of Mult. 8 and Mult. 6 for all the stars with measurements in all three multiplets. In both plots the solid line is the bisector; the cross at bottom is a representative error bar. The bisector shows the good agreement of [S/H] between Mult. 8 and Mult. 6 ( left). The systematic difference of [S/H] derived from Mult. 1 is shown by the linear correlation (grey line).
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In the text

$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f9.eps} \end{figure}$ Figure 9: Comparison of [S/H] value from our measurements and the determination of Nissen et al. (2004).
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,height=14.8cm,clip]{2905_f10.eps} \end{figure}$ Figure 10: Bottom panel: [S/Fe] versus [Fe/H]. The measures of the present paper are indicated as asterisks, crosses are the data taken from the literature (Table A.2). The typical error bar is shown in the lower left corner. Top panel: [S/H] versus [Fe/H] for all stars considered. Two different linear trends can be distinguished: the thick line is a fit to all stars with [Fe/H]> -1, the thin line to those with [Fe/H $]\le -1.0$ .
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In the text

$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f11.eps} \end{figure}$ Figure 11: The [S/Fe] ratio versus effective temperature for all the stars in Table A.2. No trend is discernible.
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In the text

$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f12.eps} \end{figure}$ Figure 12: Fit of the 921.2 nm line (grey line) of four of the most metal poor stars that lie in different places in the plot [S/Fe] versus [Fe/H]. Dashed lines are synthetic spectra computed with $\pm$ 0.1 dex the best fitting abundance. As one can see the four fits are good, and the abundance deduced by these fits should be reliable.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f13.eps} \end{figure}$ Figure 13: [S/Fe] versus [Fe/H] for the stars classified on the basis of their Galactic orbits: open circles are the thin disc stars, crosses the dissipative component, triangles the accretion component, and the asterisks are the stars which do not fall in any of these categories.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f14.eps} \end{figure}$ Figure 14: [S/Fe] as a function of perigalactic distance Rmin, in kpc. The different populations are marked as in Fig. 13.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f15.eps} \end{figure}$ Figure 15: [S/Fe] as a function of apogalactic distance Rmax, in kpc. The different populations are distinguished as in Fig. 13.
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In the text

$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f16.eps} \end{figure}$ Figure 16: [Mg/Fe] versus [Fe/H] from Gratton et al. (2003); circled stars are those in common with the present study.
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In the text

$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f17.eps} \end{figure}$ Figure 17: [Mg/H] versus [Fe/H] for the stars in the compilation of Venn et al. (2004) (crosses) and [S/H] versus [Fe/H] (open hexagons) from the compilation in Table A.2.
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In the text

$\begin{figure} \par\includegraphics[width=13cm,clip]{2905_f18.eps} \end{figure}$ Figure 18: [S/Mg] versus [Mg/H] ( left panel) and [Fe/H] ( right panel). Mg abundances are from Gratton et al. (2003).
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In the text

$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f19.eps} %\end{figure}$ Figure 19: [S/Zn] versus [Zn/H]. Zn abundances are from Gratton et al. (2003).
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In the text

$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f20.eps} \end{figure}$ Figure 20: [S/Fe] versus [S/Zn]. Zn abundances are from Gratton et al. (2003). The solid line is a least squares fit to the data: [S/Fe]=0.68 [S/Zn]+0.24.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f21.eps} \end{figure}$ Figure A.1: G 76 -21 is suspected of being a double-lined system. In fact, lines: Fe II 448.9183 nm, Fe II 449.1405 nm, and Cr I 449.6852 nm show a flat and double core. The grey line is a synthetic spectrum computed with the appropriate parameters.

In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f22.eps} \end{figure}$ Figure A.2: HD 219175 shows a flat core of Si I 868.6352 nm, Fe I 868.8624 nm and S I 869.3931 nm and 869.4626 nm.

In the text

$\begin{figure} \par\includegraphics[angle=-90,width=15cm,clip]{2905_f1.eps} \end{figure}$	Figure 1: Grotrian diagram of the Quintet system. The decays that give rise to the lines of multiplets 1, 6, 8 are indicated in grey. The partial Grotrian diagram of the quintet system, including the lines of astrophysical interest, was adapted from Atomic energy-level and Grotrian diagrams by Bashkin & Stoner (1978).
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f2.eps} \end{figure}$	Figure 2: Fit in the region of 670 nm of the star HD 25704 (black observed spectrum, grey fitted spectrum). The Fe I 675.0152 is in good agreement with the [Fe/H] utilized, so we fitted the whole range including the S I lines of Mult. 8 and the lines of other elements as well.
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f3.eps} \end{figure}$	Figure 3: Fit in the region of Mult. 8 of the star HD 10607; black is the observed spectrum and grey the fit.
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f4.eps} \end{figure}$	Figure 4: Fit in the region of Mult. 6 of the star HD 10607. The solid line is the observed spectrum after subtraction of telluric lines; dotted line is observed spectrum, grey is the fit.
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$\begin{figure} \par\includegraphics[width=7cm,height=5cm,clip]{2905_f5.eps} \end{figure}$	Figure 5: Fit of the 922.8 nm S I line in star BD +17 408. It may be appreciated that the synthetic spectrum provides a good fit to the wings of Paschen $\zeta$ , while not to the core. This is not surprising since our synthetic spectra are computed in LTE and the core of Paschen lines is predicted to be affected by NLTE effects (see for example Johnson & Kinglesmith 1965).
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$\begin{figure} \par\includegraphics[width=7cm,height=5cm,clip]{2905_f6.eps} \end{figure}$	Figure 6: Two spectra with parameters: $T_{\rm eff}=6016$ K, log g = 4.04, and [Fe/H] = -1.5, the G 126 -62 star parameters. The black one is the one we used to fit the sulphur abundance, while the grey one is built without the 922.9017 nm Paschen $\zeta$ .
Open with DEXTER

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f7.eps} \end{figure}$	Figure 7: Microturbulence effect on sulphur lines; the synthetic spectra plotted have: $T_{\rm eff}=5810$ K, log g = 4.50, [Fe/H]=-1.0, which are the parameters of the star HD 205650. This star has been selected to show microturbulence effect, because its parameters fall near the average of our sample.
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$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f9.eps} \end{figure}$	Figure 9: Comparison of [S/H] value from our measurements and the determination of Nissen et al. (2004).
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$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f11.eps} \end{figure}$	Figure 11: The [S/Fe] ratio versus effective temperature for all the stars in Table A.2. No trend is discernible.
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$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f12.eps} \end{figure}$	Figure 12: Fit of the 921.2 nm line (grey line) of four of the most metal poor stars that lie in different places in the plot [S/Fe] versus [Fe/H]. Dashed lines are synthetic spectra computed with $\pm$ 0.1 dex the best fitting abundance. As one can see the four fits are good, and the abundance deduced by these fits should be reliable.
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f13.eps} \end{figure}$	Figure 13: [S/Fe] versus [Fe/H] for the stars classified on the basis of their Galactic orbits: open circles are the thin disc stars, crosses the dissipative component, triangles the accretion component, and the asterisks are the stars which do not fall in any of these categories.
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f14.eps} \end{figure}$	Figure 14: [S/Fe] as a function of perigalactic distance Rmin, in kpc. The different populations are marked as in Fig. 13.
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2905_f15.eps} \end{figure}$	Figure 15: [S/Fe] as a function of apogalactic distance Rmax, in kpc. The different populations are distinguished as in Fig. 13.
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$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f16.eps} \end{figure}$	Figure 16: [Mg/Fe] versus [Fe/H] from Gratton et al. (2003); circled stars are those in common with the present study.
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$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f17.eps} \end{figure}$	Figure 17: [Mg/H] versus [Fe/H] for the stars in the compilation of Venn et al. (2004) (crosses) and [S/H] versus [Fe/H] (open hexagons) from the compilation in Table A.2.
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$\begin{figure} \par\includegraphics[width=13cm,clip]{2905_f18.eps} \end{figure}$	Figure 18: [S/Mg] versus [Mg/H] ( left panel) and [Fe/H] ( right panel). Mg abundances are from Gratton et al. (2003).
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$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f19.eps} %\end{figure}$	Figure 19: [S/Zn] versus [Zn/H]. Zn abundances are from Gratton et al. (2003).
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$\begin{figure} \par\includegraphics[width=7cm,clip]{2905_f20.eps} \end{figure}$	Figure 20: [S/Fe] versus [S/Zn]. Zn abundances are from Gratton et al. (2003). The solid line is a least squares fit to the data: [S/Fe]=0.68 [S/Zn]+0.24.
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