All Figures

$\begin{figure} \par\resizebox{16.cm}{5.7cm} {\includegraphics{0074-fi1-1.ps}}\p... ....ps}}\par\resizebox{16.cm}{5.7cm} {\includegraphics{0074-fi1-3.ps}}\end{figure}$ Figure 1: An example of the reduced spectra in the region of the Ca II H and K lines, the Mg I triplet, and in the region of the forbidden oxygen line. The abscissa is the wavelength in nm. Telluric lines are indicated.
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In the text

$\begin{figure} \par\resizebox{6.cm}{6.0cm} {\includegraphics{0074-fi2-1.ps}}\pa... ...2.ps}}\par\resizebox{6.cm}{6.0cm} {\includegraphics{0074-fi2-3.ps}}\end{figure}$ Figure 2: Comparison between our EWs and those of Johnson (2002), Carretta et al. (2002), and McWilliam et al. (1995). The one-to-one relation is shown by a dashed line, the mean curve (least squares) by a full thin line. The value of the slope (a) and zero point shift (b) of the regression are given, as well as the standard deviation of the fit ( $\sigma$ ).
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In the text

$\begin{figure} \par\resizebox{7.cm}{4.0cm} {\includegraphics{0074-fi3-1.ps}}\pa... ...2.ps}}\par\resizebox{7.cm}{4.0cm} {\includegraphics{0074-fi3-3.ps}}\end{figure}$ Figure 3: Comparison of FeI abundance for CS 22878-101 vs. excitation potential, equivalent width, and wavelength. The parameters adopted for the model are $T_{{\rm eff}}$ = 4800 K, log g = 1.3, $v_ {{\rm t}}$ = 2.0 km s^-1, and [Fe/H]_m = -3.0. The line at [Fe/H] = -3.29 represents the mean value of the iron abundance deduced from the Fe I lines.
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In the text

$\begin{figure} \par\resizebox{8.cm}{4cm} {\includegraphics{0074-fi4.ps}}\end{figure}$ Figure 4: [C/Fe] plotted vs. effective temperature. In the coolest stars ( $T_{{\rm eff}}< 4800$ K), the [C/Fe] ratio decreases due to mixing, which has likely brought processed material to the surface from deep layers where C is converted into N.
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In the text

$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi5.ps}}\end{figure}$ Figure 5: [C/Fe] plotted vs. [Fe/H]. The "C-rich'' objects CS 22892-052 and CS 22949-037 were excluded when computing the regression line. The slope of the line is not significant; the mean value of [C/Fe] is $\approx$ 0.2, and the dispersion is 0.37 dex, Note that the C abundance for CD-38:245 ([Fe/H) = -4.19) is only an upper limit.
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In the text

$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi6-1.ps}}\par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi6-2.ps}}\end{figure}$ Figure 6: [O/Fe] plotted vs. [Fe/H], without and with a correction for stellar surface inhomogeneities (Nissen et al. 2002). The correction is uncertain since it has been computed for dwarfs. The slope of the regression line (dashed) is small and not significant.
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In the text

$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi7-1.ps}}\par... ...-3.ps}}\par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi7-4.ps}}\end{figure}$ Figure 7: [Mg/Fe], [Si/Fe], [Ca/Fe] and [Ti/Fe] plotted vs. [Fe/H]. The peculiar star CS 22949-037 is not included in the computations of the scatter and of the regression line (dashed) for Mg. The star CS 22169-035 is deficient in all the light "even'' elements.
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In the text

$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi8-1.ps}}\par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi8-2.ps}}\end{figure}$ Figure 8: [Na/Fe] and [Al/Fe] plotted vs. [Fe/H]. The LTE abundances of these elements have been determined from resonance lines, but corrections for NLTE effects have been applied.
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In the text

$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi9-1.ps}}\par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi9-2.ps}}\end{figure}$ Figure 9: [K/Fe] and [Sc/Fe] plotted vs. [Fe/H]. An NLTE correction has been applied to our potassium abundance measurements (see text).
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In the text

$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi10-1.ps}}\par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi10-2.ps}}\end{figure}$ Figure 10: [Cr/Fe] and [Mn/Fe] plotted vs. [Fe/H]. For Mn the hyperfine structure has been taken into account, and only the lines with an excitation potential larger than 2.2 have been used. When these lines are too weak (open symbols) the abundance has been deduced from the resonance lines and corrected for a systematic effect.
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In the text

$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi11.ps}}\end{figure}$ Figure 11: [Cr/Mn] plotted vs. [Fe/H]. The symbols are the same as in Fig. 10. The ratio Cr/Mn is almost constant and close to the solar value.
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In the text

$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi12-1.ps}}\pa... ...2.ps}}\par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi12-3.ps}}\end{figure}$ Figure 12: [Co/Fe], [Ni/Fe], and [Zn/Fe] plotted vs. [Fe/H]. These ratios increase ([Co/Fe], [Zn/Fe]) or remain essentially constant ([Ni/Fe]) with decreasing metallicity.
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In the text

$\begin{figure} \par\resizebox{5.8cm}{2.90cm} {\includegraphics{0074-fi13-01.ps}... ...4.ps}}\resizebox{5.8cm}{2.90cm} {\includegraphics{0074-fi13-15.ps}}\end{figure}$ Figure 13: Abundance ratios [X/Mg] plotted vs. [Mg/H]. The scale is the same for all the plots: the amplitude in the coordinate [X/Mg] is 2.2 dex. For Mn the symbols are the same as in Fig. 10.
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In the text

$\begin{figure} \par\resizebox{6.cm}{6.cm} {\includegraphics{0074-fi14.ps}}\end{figure}$ Figure 14: [C/Mg] vs. [Mg/Fe] for all stars of our sample with temperatures higher than 4800 K (and thus presumably not mixed). Filled circles represent the most metal-poor stars ([Fe/H] $\leq$ -3.0), open circles the stars with [Fe/H] > -3.0. The variation of [C/Mg] is larger than expected from the computations of Karlsson & Gustafsson (2001), suggesting that the scatter in [C/Mg] is not explained by the theoretical yields.
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In the text

$\begin{figure} \par\resizebox{7.cm}{3.5cm} {\includegraphics{0074-fi15-1.ps}}\par\resizebox{7.cm}{3.5cm} {\includegraphics{0074-fi15-2.ps}}\end{figure}$ Figure 15: Mean [X/Mg] values for [Mg/H]<-3 (Fig. 7 and Table 10) compared to the model yields by: a) Woosley & Weaver for 15 (dotted line), 25 (dashed), and 35 $M_{\odot }$ SNe (full), and b) Chieffi & Limongi for 15 (dotted line), 20 (dotted-dashed), 35 (dashed), and 50 $M_{\odot }$ (full).
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In the text

$\begin{figure} \par\resizebox{16.cm}{5.7cm} {\includegraphics{0074-fi1-1.ps}}\p... ....ps}}\par\resizebox{16.cm}{5.7cm} {\includegraphics{0074-fi1-3.ps}}\end{figure}$	Figure 1: An example of the reduced spectra in the region of the Ca II H and K lines, the Mg I triplet, and in the region of the forbidden oxygen line. The abscissa is the wavelength in nm. Telluric lines are indicated.
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$\begin{figure} \par\resizebox{6.cm}{6.0cm} {\includegraphics{0074-fi2-1.ps}}\pa... ...2.ps}}\par\resizebox{6.cm}{6.0cm} {\includegraphics{0074-fi2-3.ps}}\end{figure}$	Figure 2: Comparison between our EWs and those of Johnson (2002), Carretta et al. (2002), and McWilliam et al. (1995). The one-to-one relation is shown by a dashed line, the mean curve (least squares) by a full thin line. The value of the slope (a) and zero point shift (b) of the regression are given, as well as the standard deviation of the fit ( $\sigma$ ).
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$\begin{figure} \par\resizebox{7.cm}{4.0cm} {\includegraphics{0074-fi3-1.ps}}\pa... ...2.ps}}\par\resizebox{7.cm}{4.0cm} {\includegraphics{0074-fi3-3.ps}}\end{figure}$	Figure 3: Comparison of FeI abundance for CS 22878-101 vs. excitation potential, equivalent width, and wavelength. The parameters adopted for the model are $T_{{\rm eff}}$ = 4800 K, log g = 1.3, $v_ {{\rm t}}$ = 2.0 km s^-1, and [Fe/H]_m = -3.0. The line at [Fe/H] = -3.29 represents the mean value of the iron abundance deduced from the Fe I lines.
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$\begin{figure} \par\resizebox{8.cm}{4cm} {\includegraphics{0074-fi4.ps}}\end{figure}$	Figure 4: [C/Fe] plotted vs. effective temperature. In the coolest stars ( $T_{{\rm eff}}< 4800$ K), the [C/Fe] ratio decreases due to mixing, which has likely brought processed material to the surface from deep layers where C is converted into N.
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$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi5.ps}}\end{figure}$	Figure 5: [C/Fe] plotted vs. [Fe/H]. The "C-rich'' objects CS 22892-052 and CS 22949-037 were excluded when computing the regression line. The slope of the line is not significant; the mean value of [C/Fe] is $\approx$ 0.2, and the dispersion is 0.37 dex, Note that the C abundance for CD-38:245 ([Fe/H) = -4.19) is only an upper limit.
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$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi6-1.ps}}\par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi6-2.ps}}\end{figure}$	Figure 6: [O/Fe] plotted vs. [Fe/H], without and with a correction for stellar surface inhomogeneities (Nissen et al. 2002). The correction is uncertain since it has been computed for dwarfs. The slope of the regression line (dashed) is small and not significant.
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$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi7-1.ps}}\par... ...-3.ps}}\par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi7-4.ps}}\end{figure}$	Figure 7: [Mg/Fe], [Si/Fe], [Ca/Fe] and [Ti/Fe] plotted vs. [Fe/H]. The peculiar star CS 22949-037 is not included in the computations of the scatter and of the regression line (dashed) for Mg. The star CS 22169-035 is deficient in all the light "even'' elements.
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$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi8-1.ps}}\par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi8-2.ps}}\end{figure}$	Figure 8: [Na/Fe] and [Al/Fe] plotted vs. [Fe/H]. The LTE abundances of these elements have been determined from resonance lines, but corrections for NLTE effects have been applied.
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$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi9-1.ps}}\par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi9-2.ps}}\end{figure}$	Figure 9: [K/Fe] and [Sc/Fe] plotted vs. [Fe/H]. An NLTE correction has been applied to our potassium abundance measurements (see text).
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$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi10-1.ps}}\par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi10-2.ps}}\end{figure}$	Figure 10: [Cr/Fe] and [Mn/Fe] plotted vs. [Fe/H]. For Mn the hyperfine structure has been taken into account, and only the lines with an excitation potential larger than 2.2 have been used. When these lines are too weak (open symbols) the abundance has been deduced from the resonance lines and corrected for a systematic effect.
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$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi11.ps}}\end{figure}$	Figure 11: [Cr/Mn] plotted vs. [Fe/H]. The symbols are the same as in Fig. 10. The ratio Cr/Mn is almost constant and close to the solar value.
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$\begin{figure} \par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi12-1.ps}}\pa... ...2.ps}}\par\resizebox{8.cm}{4.cm} {\includegraphics{0074-fi12-3.ps}}\end{figure}$	Figure 12: [Co/Fe], [Ni/Fe], and [Zn/Fe] plotted vs. [Fe/H]. These ratios increase ([Co/Fe], [Zn/Fe]) or remain essentially constant ([Ni/Fe]) with decreasing metallicity.
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$\begin{figure} \par\resizebox{5.8cm}{2.90cm} {\includegraphics{0074-fi13-01.ps}... ...4.ps}}\resizebox{5.8cm}{2.90cm} {\includegraphics{0074-fi13-15.ps}}\end{figure}$	Figure 13: Abundance ratios [X/Mg] plotted vs. [Mg/H]. The scale is the same for all the plots: the amplitude in the coordinate [X/Mg] is 2.2 dex. For Mn the symbols are the same as in Fig. 10.
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$\begin{figure} \par\resizebox{7.cm}{3.5cm} {\includegraphics{0074-fi15-1.ps}}\par\resizebox{7.cm}{3.5cm} {\includegraphics{0074-fi15-2.ps}}\end{figure}$	Figure 15: Mean [X/Mg] values for [Mg/H]<-3 (Fig. 7 and Table 10) compared to the model yields by: a) Woosley & Weaver for 15 (dotted line), 25 (dashed), and 35 $M_{\odot }$ SNe (full), and b) Chieffi & Limongi for 15 (dotted line), 20 (dotted-dashed), 35 (dashed), and 50 $M_{\odot }$ (full).
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