All Figures

$\begin{figure} \par\includegraphics[width=9cm,clip]{9779fi1a.eps}\par\vspace*{4.5mm} \includegraphics[width=8.54cm,clip]{9779fi1b.eps}\end{figure}$ Figure 1: Parts of the rectified FEROS spectrum (dashed lines) showing the regions around several expected He I lines. For better visualization, we convolved the FEROS data to a resolution of R = 4900 as was used by ZSW (solid lines).
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In the text

$\begin{figure} \par\includegraphics[width=9cm,clip]{9779fig2.eps}\end{figure}$ Figure 2: Balmer lines in the spectrum of S 23.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{9779fig3.eps}\end{figure}$ Figure 3: Effective temperature dependence of the line ratio Mg II $\lambda$ 4481 over He I $\lambda$ 4472 calculated from model stellar atmospheres with $\log g = 2.5$ at solar abundances. The behaviour between spectral type and effective temperature taken from Evans & Howarth (2003) is indicated in the bottom label for solar abundance, and in the top label for SMC abundance. The two boxes indicate the observed ratios with their errors for the ZSW spectrum taken in 1989 and our spectrum taken in 2000, respectively.
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In the text

$\begin{figure} \par\includegraphics[width=17.5cm,clip]{9779fig4.eps}\end{figure}$ Figure 4: Fitting process of the Mg II $\lambda$ 4481 line with a pure rotation profile ( left panel), a pure Gaussian profile ( mid panel), and our best fit model ( right panel) with a profile consisting mainly of stellar rotation plus some macro-turbulence.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{9779fig5.eps}\end{figure}$ Figure 5: Maximum velocity caused by macro-turbulence to the Mg II $\lambda$ 4481 line for a sample of B-type supergiants. The data are taken from Ryans et al. (2002).
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{9779fig6.eps}\end{figure}$ Figure 6: Distribution of projected rotational velocities with spectral type of a sample of galactic (Abt et al. 2002; Verdugo et al. 1999) and SMC (Hunter et al. 2008; Venn 1999) supergiants. The big spot with errorbars is the value of S 23 derived from our analysis.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{9779fig7.eps}\end{figure}$ Figure 7: Shape of S 23 rotating with 75% of its critical velocity. Also included are the assumed positions of the observers with respect to the rotation axis of the star in the two periods of optical observations.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{9779fig8.eps}\end{figure}$ Figure 8: Distribution of the surface parameters (effective temperature, escape velocity, hydrogen density, and mass flux) with co-latitude, $\theta$ , normalised to their polar values. All parameters are found to drop from pole to equator (for details on their calculation see Kraus 2006).
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In the text

$\begin{figure} \par\includegraphics[width=9cm,clip]{9779fi1a.eps}\par\vspace*{4.5mm} \includegraphics[width=8.54cm,clip]{9779fi1b.eps}\end{figure}$	Figure 1: Parts of the rectified FEROS spectrum (dashed lines) showing the regions around several expected He I lines. For better visualization, we convolved the FEROS data to a resolution of R = 4900 as was used by ZSW (solid lines).
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$\begin{figure} \par\includegraphics[width=9cm,clip]{9779fig2.eps}\end{figure}$	Figure 2: Balmer lines in the spectrum of S 23.
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$\begin{figure} \par\includegraphics[width=17.5cm,clip]{9779fig4.eps}\end{figure}$	Figure 4: Fitting process of the Mg II $\lambda$ 4481 line with a pure rotation profile ( left panel), a pure Gaussian profile ( mid panel), and our best fit model ( right panel) with a profile consisting mainly of stellar rotation plus some macro-turbulence.
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{9779fig5.eps}\end{figure}$	Figure 5: Maximum velocity caused by macro-turbulence to the Mg II $\lambda$ 4481 line for a sample of B-type supergiants. The data are taken from Ryans et al. (2002).
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{9779fig6.eps}\end{figure}$	Figure 6: Distribution of projected rotational velocities with spectral type of a sample of galactic (Abt et al. 2002; Verdugo et al. 1999) and SMC (Hunter et al. 2008; Venn 1999) supergiants. The big spot with errorbars is the value of S 23 derived from our analysis.
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{9779fig7.eps}\end{figure}$	Figure 7: Shape of S 23 rotating with 75% of its critical velocity. Also included are the assumed positions of the observers with respect to the rotation axis of the star in the two periods of optical observations.
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{9779fig8.eps}\end{figure}$	Figure 8: Distribution of the surface parameters (effective temperature, escape velocity, hydrogen density, and mass flux) with co-latitude, $\theta$ , normalised to their polar values. All parameters are found to drop from pole to equator (for details on their calculation see Kraus 2006).
Open with DEXTER