All Figures

$\begin{figure} \par\includegraphics[width=6.8cm,clip]{m3704f1.ps}\end{figure}$ Figure 1: The central line indices $\ensuremath{{\rm Mg}~ b}$ (panel a)), $\ensuremath{\langle {\rm Fe}\rangle}$ (panel b)), and $\ensuremath {{\rm H}\beta }$ (panel c)) versus the velocity dispersion $\sigma$ for the 35 early type galaxies of the Coma cluster sample. Filled triangles indicate the 2 cDs, filled circles Es, open circles S0s and open stars E/S0s. The solid lines are linear least square fits (see text). The long and short dashed lines show the contributions to the Mg $-\sigma$ and Fe $-\sigma$ relations due to metallicity and $\ensuremath {\alpha /{\rm Fe}}$ ratio variations, respectively (see Sect. 4.2.2).
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In the text

$\begin{figure} \par\includegraphics[width=11.8cm,clip]{m3704f2.ps} \end{figure}$ Figure 2: Distributions of the fitted logarithmic gradients of the indices, $\ensuremath {{\rm H}\beta }$ ( a), $\ensuremath{{\rm Mg}~ b}$ ( b), $\ensuremath{\langle {\rm Fe}\rangle}$ ( c), and the velocity dispersion $\sigma$ ( d). The median of the gradients is indicated in the individual panels.
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In the text

$\begin{figure} \par\includegraphics[width=6.8cm,clip]{m3704f3.ps} \end{figure}$ Figure 3: The fitted logarithmic gradient of the Mg_b ( a), <Fe>( b) and H $\beta$ ( c) index versus the fitted logarithmic gradient of the velocity dispersion $\sigma$ . Symbols as in Fig. 1. The lines show the relations $\langle\triangle \ensuremath{{\rm Mg}~ b}\rangle \approx 0.58 \times \langle\triangle\sigma\rangle$ and $\langle\triangle \langle {\rm Fe}\rangle\rangle \approx 0.46 \times \langle\triangle\sigma\rangle$ (see Fig. 2).
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In the text

$\begin{figure} \par\includegraphics[width=8.35cm,clip]{m3704f4a.ps}\hspace*{0.4cm} \includegraphics[width=8.4cm,clip]{m3704f4b.ps} \end{figure}$ Figure 4: The distribution of the central values of $\ensuremath {{\rm H}\beta }$ and $\ensuremath {[{\rm MgFe}]^{\prime }}$ indices ( left panel) and $\ensuremath{\langle {\rm Fe}\rangle}$ and $\ensuremath{{\rm Mg}~ b}$ indices ( right panel) averaged over 0.1 $a_{\rm e}$ of the 35 early type galaxies of the Coma cluster sample. Symbols as in Fig. 1. The lines indicate models (TMB) of constant ages and metallicities (see labels). Models in the right panel are for fixed age (12 Gyr) and various $\ensuremath {\alpha /{\rm Fe}}$ ratios (see labels).
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In the text

$\begin{figure} \par\includegraphics[width=6.8cm,clip]{m3704f5.ps}\par\end{figure}$ Figure 5: Central ages, metallicities ([Z/H]) and the $[\ensuremath {\alpha /{\rm Fe}} ]$ ratios listed in Table B.2 plotted versus the central velocity dispersion $\sigma$ . Symbols as in Fig. 1. Straight lines indicate the linear least square fits for panels b) (excluding the low-age, high metallicity objects) and c) (excluding the Objects GMP 3329, 2921, 3561 and 3201, small symbols, see Sect. 4.2.1), giving the following relations: $[{Z/{\rm H}}] = -1.56 (\pm 0.27) + 0.77 (\pm 0.10) \times \log(\sigma)$ , $[{\rm \alpha/Fe}] = -0.59 (\pm 0.21) + 0.36 (\pm 0.09) \times \log(\sigma)$ .
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In the text

$\begin{figure} \par\includegraphics[width=13.6cm,clip]{m3704f6.ps}\end{figure}$ Figure 6: Central ages, metallicities ([Z/H]) and the $[\ensuremath {\alpha /{\rm Fe}} ]$ ratios listed in Table B.2 plotted versus each other. Symbols as in Fig. 1. The linear least square fits for panel a) and c) give following relations a) ${\rm age} = 12.9 (\pm 1.2) -18.2 (\pm 4.7) \times [Z/{\rm H}]$ and c) $[\ensuremath {\alpha /{\rm Fe}} ] = 0.16 (\pm 0.02) + 0.008 (\pm 0.002) \times {\rm age}$ and are indicated by the straight lines. Object GMP 3329, 2921, 3561 and 3201 (small symbols) were not included in the fit (see Sect. 4.2.1).
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In the text

$\begin{figure} \par\includegraphics[width=16cm,clip]{m3704f7.ps} \end{figure}$ Figure 7: Distributions of the gradients derived for age (Gyr, panel a)), metallicity (panel b)), and $\ensuremath {\alpha /{\rm Fe}}$ ratio (panel c)). The median values are given in the panels, respectively. The solid lines are obtained by summing up the distributions of the gradients folded with their Gaussian errors.
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In the text

$\begin{figure} \par\includegraphics[width=8.7cm,clip]{m3704f8a.ps}\hspace*{0.4cm} \includegraphics[width=8.7cm,clip]{m3704f8b.ps} \end{figure}$ Figure 8: Left panel: metallicity gradient as a function of the logarithmic gradient in velocity dispersion. Symbols as in Fig. 1. Galaxies outside one $\sigma$ about the mean of the age gradients' distribution (see Fig. 7) are plotted with smaller symbols. The typical error is given in the lower right-hand corner. Right panel: residuals from the correlation shown in the left panel by the solid line as a function of the age gradient.
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In the text

$\begin{figure} \par\includegraphics[width=11.8cm,clip]{m3704f2.ps} \end{figure}$	Figure 2: Distributions of the fitted logarithmic gradients of the indices, $\ensuremath {{\rm H}\beta }$ ( a), $\ensuremath{{\rm Mg}~ b}$ ( b), $\ensuremath{\langle {\rm Fe}\rangle}$ ( c), and the velocity dispersion $\sigma$ ( d). The median of the gradients is indicated in the individual panels.
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$\begin{figure} \par\includegraphics[width=16cm,clip]{m3704f7.ps} \end{figure}$	Figure 7: Distributions of the gradients derived for age (Gyr, panel a)), metallicity (panel b)), and $\ensuremath {\alpha /{\rm Fe}}$ ratio (panel c)). The median values are given in the panels, respectively. The solid lines are obtained by summing up the distributions of the gradients folded with their Gaussian errors.
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