All Figures

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f1.ps} \end{figure}$ Figure 1: Distribution in the $T_{\rm eff}$ - $\log_{\rm 10} g$ diagram of the 1503 stars in the ELODIE library in four bins of metallicity.
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In the text

$\begin{figure} \par\includegraphics[width=16.8cm,clip]{MS3921f2.ps} \end{figure}$ Figure 2: Comparison of Lick indices measured on the ELODIE spectra with the reference Lick/IDS indices (Worthey et al. 1994) for 187 stars in common. The dotted lines are $y=x\pm \sigma _{{\rm IDS}}$ where $\sigma _{\rm IDS}$ is the uncertainty on the Lick/IDS indices. For each panel, we give the slope of the linear regression and the dispersion $\sigma$ around it. Ideally, $\sigma / \sigma _{\rm IDS} \simeq 1.$
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In the text

$\begin{figure} \par\includegraphics[width=18cm,clip]{MS3921f3.ps} \end{figure}$ Figure 3: PEGASE-HR high-resolution spectrum of a 10 Gyr-old SSP of solar metallicity compared to the low resolution spectrum from PEGASE.2. The flux is given in units of $10^{-5}~{L}_\odot$ Å $^{-1}~M_\odot^{-1}$ , where ${L}_\odot =3.826\times 10^{33}$ erg s^-1. Grey areas correspond to the passbands of some Lick indices.
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f4.ps}\end{figure}$ Figure 4: Comparison of a portion of a smoothed PEGASE-HR SSP spectrum ( $Z_\odot$ , 3 Gyr) with the model of Bruzual & Charlot (2003). The IMF is common to both models (Salpeter 1955). a) Both models overplotted, at the same low resolution $R\simeq 2000$ . The flux is given in units of $10^{-5}~{L}_\odot$ Å $^{-1}~M_\odot^{-1}$ . b) Relative difference of the fluxes at low resolution ( $R\simeq 2000$ ). c) The original high resolution PEGASE-HR SSP spectrum (R=10 000).
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f5.ps}\end{figure}$ Figure 5: Comparison of PEGASE.2 and PEGASE-HR spectra of SSPs, at metallicities $2.5~\times$ $Z_\odot$ and $Z_\odot$ /5, and ages 0.5 Gyr and 10 Gyr. The PEGASE.2 spectra are plotted with a vertical offset (a constant in each panel) for clarity.
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In the text

$\begin{figure} \par\includegraphics[height=22cm,width=18cm,clip]{MS3921f6.ps}\end{figure}$ Figure 6: Evolution of main stellar lines and continua for an SSP as a function of age (ages = 1, 4, 13 Gyr, from light gray to black) at $Z_\odot$ ( left) and metallicity ([Fe/H] = -1.7, -0.4, 0.4, from gray to dark) at 10 Gyr ( right). Line identifications are from the revised ILLSS catalogue (Coluzzi 1999). Grey areas show the blue and red pseudo-continua of the Lick indices and solid vertical lines delimit their central passband. In some cases (H $\gamma _{\rm A}$ , H $\delta _{\rm A}$ ), significant evolution with age is observed within the pseudo-continua (see text).
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f7.ps}\end{figure}$ Figure 7: Comparison of the integrated optical flux predicted by PEGASE.2 and PEGASE-HR for SSPs using $\delta F$ (4200-6700 Å). The size of the symbols scales with magnitude difference (see text in Sect. 3.1 for details).
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f8.ps}\end{figure}$ Figure 8: Comparison of the optical colors predicted by PEGASE-HR and PEGASE.2 for SSPs. The adopted color compares the fluxes integrated over 4300-4600 Å in the blue and 6400-6700 Å in the red. The size of the triangles scales with the color difference expressed in magnitudes ( $\delta {{\rm color}}$ ) between the two models. Head-up triangles are plotted when PEGASE-HR produces a redder slope than PEGASE.2.
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In the text

$\begin{figure} \par\includegraphics[height=21.8cm,width=8.75cm,clip]{MS3921f9.ps... ....5mm} \includegraphics[height=21.8cm,width=8.7cm,clip]{MS3921f10.ps}\end{figure}$ Figure 9: PEGASE-HR Lick indices (solid lines) for SSPs compared to models (dotted lines) of Worthey & Ottaviani (1997, W95), Bressan et al. (1996, BCT96), Thomas et al. (2003, TMB03) and Bruzual & Charlot (2003, BC03). The figures on the right hand side of each panel represent the quantity [Fe/H]. For BC03 only, the dashed line shows the indices computed with the Geneva tracks instead of the Padova 1994 tracks, for solar metallicity.
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f11.ps} \end{figure}$ Figure 10: Lick indices for ${\rm [Fe/H]}=0.4$ SSPs. The indices of this work (solid line), Bruzual & Charlot (2003) (dotted line) and Bressan et al. (1996) (dashed line) are shown. The shaded region shows the uncertainty in the indices associated to the uncertainty in the effective temperature of the giant stars (see text for details).
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In the text

$\begin{figure} \par\includegraphics[width=8.6cm,clip]{MS3921f12.ps}\end{figure}$ Figure 11: Evolution sequences with age of the H $\beta$ equivalent width from PEGASE-HR for various metallicities (solid lines) compared to the binned globular cluster data (Bica & Alloin 1986a,b).
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f13.ps}\end{figure}$ Figure 12: Fe5270 vs. H $\beta$ indices for 193 extragalactic globular clusters (Huchra et al. 1996). Solid lines are PEGASE-HR SSP models for several ages and metallicities, as labeled on the sequences. The typical error bar for the data is plotted above the grid. For M 33 globular clusters, the size of the full squares indicates [Fe/H] (as determined by Huchra et al. 1996), following the [Fe/H] scale given by the empty squares plotted on the 14 Gyr isochrone.
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f14.ps}\end{figure}$ Figure 13: Fe5270 vs. H $\beta$ indices for 50 globular clusters of the Milky Way and M 31 (Trager et al. 1998). The grid corresponds to PEGASE-HR SSP models, with iso-age sequences (dotted lines) and iso-[Fe/H] sequences (solid lines). The median error bar for the data is plotted below the grid.
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In the text

$\begin{figure} \par\includegraphics[width=8.1cm,clip]{MS3921f15.ps}\end{figure}$ Figure 14: Lick indices of PEGASE-HR models for elliptical, Sc and single burst galaxies together with data from local elliptical galaxies (Trager et al. 2000). The age of the data is arbitrarily set by us to 13 $\pm$ 0.5 Gyr, randomly distributed (for the clarity of the plot). The presence of emission lines associated to ongoing star formation explains the low values of the H $\beta$ index predicted for evolved spiral galaxies.
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f16.ps}\end{figure}$ Figure 15: Evolution of the H $\gamma$ line as a function of metallicity for a 10 Gyr-old starburst: a) normalization at 4448 Å; b) normalization to the Lick H $\gamma _{\rm A}$ pseudo-continuum. In both panels, the spectrum is degraded to the Lick resolution. Grey zones represent the H $\gamma _{\rm A}$ Lick blue and red continuum definitions and solid vertical lines delimit the H $\gamma _{\rm A}$ feature passband.
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In the text

$\begin{figure} \par\includegraphics[width=7.3cm,clip]{MS3921f17.ps}\end{figure}$ Figure 16: H $\gamma$ indices vs. $\langle \rm Fe \rangle$ Lick index. From top to bottom, the H $\gamma$ indices are computed with the definitions of Worthey, Jones, Vazdekis, and our Very High Resolution index (see text for details). Error bars are computed from Cardiel et al. (1998) with an average S/N ratio = 50. Solid lines are iso-age sequences (1, 5, 12, 17 Gyr). Dotted lines are iso-[Fe/H] sequences (-1.7, -0.7, -0.4, 0., 0.4). The thickness of the lines increases with age and [Fe/H]. Notice the particularly flat iso-age sequences of the H $\gamma$ _VHR index, which indicates a very low Z-sensitivity.
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f18.ps}\end{figure}$ Figure 17: H $\gamma$ _VHR index (age tracer) vs. H $\gamma$ _Z index (metallicity tracer) indices. Error bars are computed from Cardiel et al. (1998) with an average S/N ratio of 50. Same symbols as in Fig. 16.
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f1.ps} \end{figure}$	Figure 1: Distribution in the $T_{\rm eff}$ - $\log_{\rm 10} g$ diagram of the 1503 stars in the ELODIE library in four bins of metallicity.
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$\begin{figure} \par\includegraphics[width=18cm,clip]{MS3921f3.ps} \end{figure}$	Figure 3: PEGASE-HR high-resolution spectrum of a 10 Gyr-old SSP of solar metallicity compared to the low resolution spectrum from PEGASE.2. The flux is given in units of $10^{-5}~{L}_\odot$ Å $^{-1}~M_\odot^{-1}$ , where ${L}_\odot =3.826\times 10^{33}$ erg s^-1. Grey areas correspond to the passbands of some Lick indices.
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$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f5.ps}\end{figure}$	Figure 5: Comparison of PEGASE.2 and PEGASE-HR spectra of SSPs, at metallicities $2.5~\times$ $Z_\odot$ and $Z_\odot$ /5, and ages 0.5 Gyr and 10 Gyr. The PEGASE.2 spectra are plotted with a vertical offset (a constant in each panel) for clarity.
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$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f7.ps}\end{figure}$	Figure 7: Comparison of the integrated optical flux predicted by PEGASE.2 and PEGASE-HR for SSPs using $\delta F$ (4200-6700 Å). The size of the symbols scales with magnitude difference (see text in Sect. 3.1 for details).
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$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f11.ps} \end{figure}$	Figure 10: Lick indices for ${\rm [Fe/H]}=0.4$ SSPs. The indices of this work (solid line), Bruzual & Charlot (2003) (dotted line) and Bressan et al. (1996) (dashed line) are shown. The shaded region shows the uncertainty in the indices associated to the uncertainty in the effective temperature of the giant stars (see text for details).
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$\begin{figure} \par\includegraphics[width=8.6cm,clip]{MS3921f12.ps}\end{figure}$	Figure 11: Evolution sequences with age of the H $\beta$ equivalent width from PEGASE-HR for various metallicities (solid lines) compared to the binned globular cluster data (Bica & Alloin 1986a,b).
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$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f14.ps}\end{figure}$	Figure 13: Fe5270 vs. H $\beta$ indices for 50 globular clusters of the Milky Way and M 31 (Trager et al. 1998). The grid corresponds to PEGASE-HR SSP models, with iso-age sequences (dotted lines) and iso-[Fe/H] sequences (solid lines). The median error bar for the data is plotted below the grid.
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$\begin{figure} \par\includegraphics[width=8.4cm,clip]{MS3921f18.ps}\end{figure}$	Figure 17: H $\gamma$ _VHR index (age tracer) vs. H $\gamma$ _Z index (metallicity tracer) indices. Error bars are computed from Cardiel et al. (1998) with an average S/N ratio of 50. Same symbols as in Fig. 16.
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