Astronomy & Astrophysics

All Figures

$\begin{figure} \par\includegraphics[width=5.9cm,clip]{4369fig1.ps}\end{figure}$ Figure 1: The CMD of NGC 2808 (taken from Bedin et al. 2000); the targets observed with the GIRAFFE/MEDUSA gratings are indicated by open circles. The colour coding indicates the setups used in the observations (red for both HR11 and HR13, blue for HR11 only, green for HR13 only).
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In the text

$\begin{figure} \par\includegraphics[width=7.4cm,clip]{4369fig2.ps}\end{figure}$ Figure 2: Run of [Fe/H] ratio and of the Iron ionization equilibrium as a function of temperatures for program stars in NGC 2808. Symbols and colour-coding refer to the setup used: (red) filled circles indicate stars with both HR11 and HR13 observations, (black) crosses for HR11 only, and (green) empty squares for HR13 only.
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{4369fig3.ps}\end{figure}$ Figure 3: The [Na/Fe] ratio as a function of [O/Fe] for red giant stars in NGC 2808. Na abundances do include the corrections for departures from LTE following Gratton et al. (1999). Upper limits in [O/Fe] for a few stars are indicated as blue arrows. The error bars take the uncertainties in atmospheric parameters and EWs into account.
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In the text

$\begin{figure} \par\includegraphics[width=7.1cm,clip]{4369fig4.ps}\end{figure}$ Figure 4: Run of [O/Fe] ( upper panel), [Na/Fe] ( middle panel), and [O/Na] ratios ( lower panel) as a function of the evolutionary status (as represented by the effective temperature) for stars in our sample in NGC 2808.
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In the text

$\begin{figure} \par\includegraphics[width=6.9cm,clip]{4369fig5.ps}\end{figure}$ Figure 5: Global Na-O anticorrelation (solid black line) superimposed on a collection of stars in about 20 globular clusters. Blue points are RGB stars from literature studies; red points are scarcely evolved stars (turnoff or subgiant stars) from Gratton et al. (2001) and Carretta et al. (2004); green points are RGB stars in NGC 2808 from the present study.
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In the text

$\begin{figure} \par\includegraphics[width=6.7cm,clip]{4369fig6.ps}\end{figure}$ Figure 6: Distribution function of the [O/Na] ratios along the Na-O anticorrelation in NGC 2808. The dashed area is the frequency histogram referred to actual detection of O in stars, whereas the empty histogram is obtained by using the global anticorrelation relationship to obtain abundances of O also for stars with no observation with HR13 and/or only upper limit in O abundance.
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In the text

$\begin{figure} \par\includegraphics[width=5.7cm,clip]{4369fig7.ps}\end{figure}$ Figure 7: Distribution function of the measured [O/Na] ratios along the Na-O anticorrelation in M 13 (Sneden et al. 2004) and NGC 2808. The O and Na abundances in M 13 are shifted to our scale by correcting for different adopted solar abundances; for M 13 we used the Na abundances corrected for departures from LTE.
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In the text

$\begin{figure} \par\includegraphics[width=5.9cm,clip]{4369fig1.ps}\end{figure}$	Figure 1: The CMD of NGC 2808 (taken from Bedin et al. 2000); the targets observed with the GIRAFFE/MEDUSA gratings are indicated by open circles. The colour coding indicates the setups used in the observations (red for both HR11 and HR13, blue for HR11 only, green for HR13 only).
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$\begin{figure} \par\includegraphics[width=7.4cm,clip]{4369fig2.ps}\end{figure}$	Figure 2: Run of [Fe/H] ratio and of the Iron ionization equilibrium as a function of temperatures for program stars in NGC 2808. Symbols and colour-coding refer to the setup used: (red) filled circles indicate stars with both HR11 and HR13 observations, (black) crosses for HR11 only, and (green) empty squares for HR13 only.
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$\begin{figure} \par\includegraphics[width=8.4cm,clip]{4369fig3.ps}\end{figure}$	Figure 3: The [Na/Fe] ratio as a function of [O/Fe] for red giant stars in NGC 2808. Na abundances do include the corrections for departures from LTE following Gratton et al. (1999). Upper limits in [O/Fe] for a few stars are indicated as blue arrows. The error bars take the uncertainties in atmospheric parameters and EWs into account.
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$\begin{figure} \par\includegraphics[width=7.1cm,clip]{4369fig4.ps}\end{figure}$	Figure 4: Run of [O/Fe] ( upper panel), [Na/Fe] ( middle panel), and [O/Na] ratios ( lower panel) as a function of the evolutionary status (as represented by the effective temperature) for stars in our sample in NGC 2808.
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$\begin{figure} \par\includegraphics[width=6.9cm,clip]{4369fig5.ps}\end{figure}$	Figure 5: Global Na-O anticorrelation (solid black line) superimposed on a collection of stars in about 20 globular clusters. Blue points are RGB stars from literature studies; red points are scarcely evolved stars (turnoff or subgiant stars) from Gratton et al. (2001) and Carretta et al. (2004); green points are RGB stars in NGC 2808 from the present study.
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$\begin{figure} \par\includegraphics[width=6.7cm,clip]{4369fig6.ps}\end{figure}$	Figure 6: Distribution function of the [O/Na] ratios along the Na-O anticorrelation in NGC 2808. The dashed area is the frequency histogram referred to actual detection of O in stars, whereas the empty histogram is obtained by using the global anticorrelation relationship to obtain abundances of O also for stars with no observation with HR13 and/or only upper limit in O abundance.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=5.7cm,clip]{4369fig7.ps}\end{figure}$	Figure 7: Distribution function of the measured [O/Na] ratios along the Na-O anticorrelation in M 13 (Sneden et al. 2004) and NGC 2808. The O and Na abundances in M 13 are shifted to our scale by correcting for different adopted solar abundances; for M 13 we used the Na abundances corrected for departures from LTE.
Open with DEXTER