Astronomy & Astrophysics

All Figures

$\begin{figure} \par\includegraphics[width=8.1cm,clip]{0370fig1.eps}\end{figure}$ Figure 1: Positions of program stars (large symbols) on the Strömgren colour-magnitude diagram of 47 Tuc. Photometry is from Grundahl et al. (1999).
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In the text

$\begin{figure} \par\includegraphics[width=7.4cm,clip]{0370fig2.eps}\end{figure}$ Figure 2: Derivation of temperature from the H $\alpha$ profile for star 1081 in 47 Tuc. Thin line: observed profile; thick lines: expected profiles computed for $T_{\rm eff}$ = 5644, 5844, and 6044 K. In the fitting we used only the regions where the relative intensity is >0.9.
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In the text

$\begin{figure} \par\includegraphics[width=4cm,clip]{0370fig3.eps}\end{figure}$ Figure 3: Comparison between EWs measured on the spectra of two dwarfs in 47 Tuc ( upper panel; stars 1012 and 1081) and two subgiants ( lower panel, stars 433 and 435). The dashed lines indicate equality, and the rms scatters about the average differences amount to 6.8 mÅ in the case of subgiants and 5.5 mÅ for TO-stars, in this example.
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In the text

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{0370fig4.eps}\end{figure}$ Figure 4: Upper panel: differences between the abundances of Fe from singly ionized and neutral lines as a function of effective temperature for stars in 47 Tuc. The solid line is the average difference for the entire sample; the lower dashed line is the average difference for the 3 dwarfs and the upper dashed line represents the average difference for the subgiant stars. The difference for the Sun, obtained from our reference analysis, is also plotted. Lower panel: the slopes of the relationship resulting between the Fe I abundances and the excitation potential as a function of adopted $T_{\rm eff}$ 's. The Sun position in the plot is also marked and the solid line is the average value for our total sample.
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In the text

$\begin{figure} \par\includegraphics[width=7.45cm,clip]{0370fig5.eps}\end{figure}$ Figure 5: [Na/Fe] ratio as a function of [O/Fe]. Panel a): filled circles are turn-off stars and open circles are subgiant in 47 Tuc from the present study. The arrows represent the stars with only upper limits in derived O abundances. Panel b): overimposed (open squares) to stars of this study are 3 red giant stars from Carretta (1994). Panel c): 10 red giants (open triangles) of the study of Sneden et al. (1994) in M 71 (NGC 6838), from the re-analysis by Carretta (1994), are added to the stars of the previous sources.
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In the text

$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0370fig6.eps}\end{figure}$ Figure 6: Run of the [Mg/Fe] ratio as a function of [Al/Fe], for stars in 47 Tuc. Symbols are as in the previous figure.
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In the text

$\begin{figure} \par\includegraphics[width=8.55cm,clip]{0370fig7.eps}\end{figure}$ Figure 7: Run of the overabundances of individual $\alpha$ -elements as well as of the average of Mg, Si, Ca and Ti as a function of [Fe/H]. Open squares are the field stars belonging to the dissipative component of the Galaxy studied by Gratton et al. (2003b). The big filled circle represents present data for 47 Tuc. Note the position of the cluster at the upper envelope of the field star distribution for Ti and the average of $\alpha$ -elements. Typical error bars for the cluster average abundances are smaller than the symbol size.
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In the text

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{0370fig8.eps}\end{figure}$ Figure 8: Differences for several elements between the clusters analyzed in Paper I and in the present work, and field stars of similar metallicities (from Gratton et al. 2003b). Differences were arbitrarily shifted for display purposes. Solid lines connect Fe-group elements having consecutive atomic number. Notice the enhanced odd-even effect, in particular in 47 Tuc: Sc, V and Mn are clearly deficient with respect to Ti, Cr and Fe.
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In the text

$\begin{figure} \par\includegraphics[width=8.25cm,clip]{0370fig9.eps}\end{figure}$ Figure 9: Run of the [Mn/Fe] ratio as a function of [Fe/H] for stars in different environments. Light crosses ([Fe/H] $\protect \la$ 0.5 dex): field stars of the dissipative component (halo/thick disk) from Gratton et al. (2003b). Light crosses (-0.6 $\protect \la$ [Fe/H] $\protect \la$ 0): field thin disk stars from Feltzing & Gustaffson (1998; FG98). Light crosses ([Fe/H] $\protect \ga$ 0): thin disk stars from Reddy et al. (2000). Open squares: field stars of the accretion component, from Gratton et al. (2003b). Open circles: red giants in several dSphs from Shetrone et al. (2001, 2003). Open five-pointed stars: two low $\alpha$ -elements stars from Ivans et al. (2003). Filled squares: bulge red giants, from McW03. Filled triangles: giants in the Sgr dwarf galaxy, from McW03. Filled circles: giants in Sgr from Bonifacio et al. (2000). Open "nova explosions'': average abundances for galactic globular clusters: NGC 6397 and NGC 6752 (Gratton et al. 2001, [Fe/H] =-2.03 and -1.42 respectively), Pal 5 (Smith et al. 2002, [Fe/H] =-1.34), M 5 (Ivans et al. 2001, [Fe/H] =-1.24), M 71 (Ramirez & Cohen 2002, [Fe/H] =-0.71), 47 Tuc (this work, [Fe/H] =-0.67) and NGC 6528 (Carretta et al. 2001, [Fe/H] = +0.07).
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In the text

$\begin{figure} \par\includegraphics[width=8.1cm,clip]{0370fig1.eps}\end{figure}$	Figure 1: Positions of program stars (large symbols) on the Strömgren colour-magnitude diagram of 47 Tuc. Photometry is from Grundahl et al. (1999).
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$\begin{figure} \par\includegraphics[width=7.4cm,clip]{0370fig2.eps}\end{figure}$	Figure 2: Derivation of temperature from the H $\alpha$ profile for star 1081 in 47 Tuc. Thin line: observed profile; thick lines: expected profiles computed for $T_{\rm eff}$ = 5644, 5844, and 6044 K. In the fitting we used only the regions where the relative intensity is >0.9.
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$\begin{figure} \par\includegraphics[width=4cm,clip]{0370fig3.eps}\end{figure}$	Figure 3: Comparison between EWs measured on the spectra of two dwarfs in 47 Tuc ( upper panel; stars 1012 and 1081) and two subgiants ( lower panel, stars 433 and 435). The dashed lines indicate equality, and the rms scatters about the average differences amount to 6.8 mÅ in the case of subgiants and 5.5 mÅ for TO-stars, in this example.
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$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0370fig6.eps}\end{figure}$	Figure 6: Run of the [Mg/Fe] ratio as a function of [Al/Fe], for stars in 47 Tuc. Symbols are as in the previous figure.
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