All Figures

$\begin{figure} \par\includegraphics[width=6.7cm,clip]{0494f1a.eps}\hspace*{4mm} \includegraphics[width=6.1cm,clip]{0494f1b.eps} \end{figure}$ Figure 1: Observations of magnetic Ap stars. Left panel: Hertzsprung-Russell diagram. Solid circles represent 19 roAp stars, open circles, 18 noAp stars, and open triangles are 3 roAp star candidates. Right panel: effective temperatures of roAp and noAp stars and roAp stars candidates. Observations are taken from Kochukhov & Bagnulo (2006) (15 roAp stars + 3 candidates) and North et al. (1997).
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f2.eps} \end{figure}$ Figure 2: Frequencies of the unstable modes predicted by our models as a function of $\log T_{\rm eff}$ . The different symbols correspond to different masses from 1.6 $M_\odot$ (cross) to 1.9 $M_\odot$ (diamond). The differences observed in the excited frequency ranges are mainly due to the different dynamical times: $\tau _{\rm dyn} = (R^3/GM)^{1/2}$ of the models.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f3.eps} \end{figure}$ Figure 3: Opacities (cm²/g) in two 1.6 $M_\odot$ models with different $T_{\rm eff}$ .
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f4.eps} \end{figure}$ Figure 4: Densities of two 1.6 $M_\odot$ models with different $T_{\rm eff}$ .
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f5.eps} \end{figure}$ Figure 5: Differential work $-{\rm d}W/{\rm d}\log T$ for the radial mode p₃₂ in two 1.6 $M_\odot$ models with different $T_{\rm eff}$ .
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f6.eps} \end{figure}$ Figure 6: Contributions to $\Re \{\delta L/L\}$ for the radial mode p₃₂ (see details in the text), model with $T_{\rm eff}=8090$ K.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f7.eps} \end{figure}$ Figure 7: $\vert\delta T/T\vert$ and $\vert\delta s/c_{\rm p}\vert$ for the radial mode p₃₂ in two 1.6 $M_\odot$ models with different $T_{\rm eff}$ .
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f8.eps} \end{figure}$ Figure 8: $\vert\delta \rho /\rho \vert$ and $\Gamma _1^{-1}\vert\delta P/P\vert$ for the radial mode p₃₂ in two 1.6 $M_\odot$ models with different $T_{\rm eff}$ .
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f9.eps} \end{figure}$ Figure 9: Comparison of the differential work $-{\rm d}W/{\rm d}\log T$ for the radial modes p₃₂and p₃₇, 1.6 $M_\odot$ model with $T_{\rm eff}=8090$ K.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f10.eps} \end{figure}$ Figure 10: $\vert\delta \rho /\rho \vert$ and $\Gamma _1^{-1}\vert\delta P/P\vert$ ( top panel) and $\phi (\delta \rho )-\phi (\delta P)$ ( bottom panel) for the modes p₃₂ and p₃₇, 1.6 $M_\odot$ model with $T_{\rm eff}=8090$ K.
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In the text

$\begin{figure} \par\includegraphics[width=6.8cm,clip]{0494f11a.eps}\hspace*{4mm}... ...s}\hspace*{4mm} \includegraphics[width=6.8cm,clip]{0494f11f.eps} \end{figure}$ Figure 11: Evolutionary tracks and theoretical instability strips of model grids with different metallicities. Left column: models with convection suppressed in the envelope; right column: standard models (with convection). Upper panel: low metallicity models, middle panel: solar metallicity models, lower panel: metal-rich models. The full gray squares represent the models for which roAp-type modes are found to be excited. The circles and triangles represent the observations in Fig. 1. For clarity, masses corresponding to the evolutionary tracks are given only for a few models. Each model grid is computed with a 0.1 $M_\odot$ step in mass. The two stars on the left middle figure correspond to the 1.6 $M_\odot$ models compared in Figs. 3 to 10.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f12.eps} \end{figure}$ Figure 12: Superposition of the instability strips deduced from models of Fig. 11. Black lines are the instability strips derived from models grids with convection suppressed, gray lines the instability strips derived from standard models.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f13.eps} \end{figure}$ Figure 13: Evolutionary tracks for three models with different masses and metallicities showing a common intersection (located by the open black square) in the HR diagram.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f14.eps} \end{figure}$ Figure 14: Opacity profiles in models with different masses and metallicities but located at the same point in the HR diagram.
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In the text

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{0494f15.eps} \end{figure}$ Figure 15: Comparison of the differential work $-{\rm d}W/{\rm d}\log T$ for three models with different global metallicities ([Fe/H]=-0.89, [Fe/H]=0.00 and [Fe/H]=0.83) at the same location in the HR diagram.
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In the text

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{0494f16.eps} \end{figure}$ Figure 16: Comparison of $\vert\delta P/P\vert$ for three models with different global metallicities ([Fe/H]=-0.89, [Fe/H]=0.00 and [Fe/H]=0.83) at the same location in the HR diagram.
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In the text

$\begin{figure} \par\includegraphics[width=6.8cm,clip]{0494fa1a.eps}\hspace*{4mm}... ...s}\hspace*{4mm} \includegraphics[width=6.8cm,clip]{0494fa1d.eps} \end{figure}$ Figure A.1: Upper panels: radiative accelerations on iron and nickel versus temperature inside four ZAMS models with different masses. The nearly horizontal curves represents the local gravity. Lower panels: derivatives of the radiative accelerations on iron and nickel. These models are computed with X=0.71 and [Fe/H]=0.00.
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In the text

$\begin{figure} \par\includegraphics[width=6.8cm,clip]{0494fa2.eps} \end{figure}$ Figure A.2: Metal accumulation profiles (mass fraction) introduced in 1.7 $M_\odot$ models. The model labelled pZ1 present a metal accumulation centered on the HI ionization region. In the pZ2 and pZ5 models the accumulation is centered respectively on the HeI and HeII accumulation region. The pZ3 and pZ4 models present an accumulation centered respectively on $\log T=4.35$ and $\log T=4.40$ .
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In the text

$\begin{figure} \par\includegraphics[width=6.8cm,clip]{0494fa3a.eps}\hspace*{4mm}... ...s}\hspace*{4mm} \includegraphics[width=6.8cm,clip]{0494fa3f.eps} \end{figure}$ Figure A.3: Figures pZ1 to pZ5: theoretical instability strips deduced from grids of models including the metal accumulation profiles shown in Fig. A.2. Figure pFe: theoretical instability strip deduced from models including the iron accumulation profile presented in Fig. B.1. The theoretical instability strips and the observations are represented following the same conventions as in Fig. 11.
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In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0494fa4.eps} \end{figure}$ Figure A.4: Opacity in models with different profiles of Z (constant, pZ1, pZ2 and pZ5 according to Fig. A.2) but located at the same point in the HR diagram.
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In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0494fa5.eps} \end{figure}$ Figure A.5: Comparison of the differential work $-{\rm d}W/{\rm d}\log T$ in models with different profiles of Z (constant, pZ1, pZ2 and pZ5 according to Fig. A.2) but located at the same point in the HR diagram.
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In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0494fb1.eps} \end{figure}$ Figure B.1: Iron accumulation profiles introduced in a 1.7 $M_\odot$ model.
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In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0494fb2.eps} \end{figure}$ Figure B.2: Opacity in a main sequence 1.7 $M_\odot$ model (labelled ``pFe'') including the iron accumulation profile displayed in Fig. B.1. For comparison the opacity of two others 1.7 $M_\odot$ models located at the same point in the HR diagram are also shown: the model labelled ``solar'' includes the AGS05 solar metal mixture, the pZ1 model is the one displayed in Fig. A.2.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f2.eps} \end{figure}$	Figure 2: Frequencies of the unstable modes predicted by our models as a function of $\log T_{\rm eff}$ . The different symbols correspond to different masses from 1.6 $M_\odot$ (cross) to 1.9 $M_\odot$ (diamond). The differences observed in the excited frequency ranges are mainly due to the different dynamical times: $\tau _{\rm dyn} = (R^3/GM)^{1/2}$ of the models.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f3.eps} \end{figure}$	Figure 3: Opacities (cm²/g) in two 1.6 $M_\odot$ models with different $T_{\rm eff}$ .
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f4.eps} \end{figure}$	Figure 4: Densities of two 1.6 $M_\odot$ models with different $T_{\rm eff}$ .
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f5.eps} \end{figure}$	Figure 5: Differential work $-{\rm d}W/{\rm d}\log T$ for the radial mode p₃₂ in two 1.6 $M_\odot$ models with different $T_{\rm eff}$ .
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f6.eps} \end{figure}$	Figure 6: Contributions to $\Re \{\delta L/L\}$ for the radial mode p₃₂ (see details in the text), model with $T_{\rm eff}=8090$ K.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f7.eps} \end{figure}$	Figure 7: $\vert\delta T/T\vert$ and $\vert\delta s/c_{\rm p}\vert$ for the radial mode p₃₂ in two 1.6 $M_\odot$ models with different $T_{\rm eff}$ .
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f8.eps} \end{figure}$	Figure 8: $\vert\delta \rho /\rho \vert$ and $\Gamma _1^{-1}\vert\delta P/P\vert$ for the radial mode p₃₂ in two 1.6 $M_\odot$ models with different $T_{\rm eff}$ .
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f9.eps} \end{figure}$	Figure 9: Comparison of the differential work $-{\rm d}W/{\rm d}\log T$ for the radial modes p₃₂and p₃₇, 1.6 $M_\odot$ model with $T_{\rm eff}=8090$ K.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f10.eps} \end{figure}$	Figure 10: $\vert\delta \rho /\rho \vert$ and $\Gamma _1^{-1}\vert\delta P/P\vert$ ( top panel) and $\phi (\delta \rho )-\phi (\delta P)$ ( bottom panel) for the modes p₃₂ and p₃₇, 1.6 $M_\odot$ model with $T_{\rm eff}=8090$ K.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f12.eps} \end{figure}$	Figure 12: Superposition of the instability strips deduced from models of Fig. 11. Black lines are the instability strips derived from models grids with convection suppressed, gray lines the instability strips derived from standard models.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f13.eps} \end{figure}$	Figure 13: Evolutionary tracks for three models with different masses and metallicities showing a common intersection (located by the open black square) in the HR diagram.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0494f14.eps} \end{figure}$	Figure 14: Opacity profiles in models with different masses and metallicities but located at the same point in the HR diagram.
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$\begin{figure} \par\includegraphics[width=7.8cm,clip]{0494f15.eps} \end{figure}$	Figure 15: Comparison of the differential work $-{\rm d}W/{\rm d}\log T$ for three models with different global metallicities ([Fe/H]=-0.89, [Fe/H]=0.00 and [Fe/H]=0.83) at the same location in the HR diagram.
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$\begin{figure} \par\includegraphics[width=7.8cm,clip]{0494f16.eps} \end{figure}$	Figure 16: Comparison of $\vert\delta P/P\vert$ for three models with different global metallicities ([Fe/H]=-0.89, [Fe/H]=0.00 and [Fe/H]=0.83) at the same location in the HR diagram.
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$\begin{figure} \par\includegraphics[width=6.8cm,clip]{0494fa1a.eps}\hspace{4mm}... ...s}\hspace{4mm} \includegraphics[width=6.8cm,clip]{0494fa1d.eps} \end{figure}$	Figure A.1: Upper panels: radiative accelerations on iron and nickel versus temperature inside four ZAMS models with different masses. The nearly horizontal curves represents the local gravity. Lower panels: derivatives of the radiative accelerations on iron and nickel. These models are computed with X=0.71 and [Fe/H]=0.00.
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$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0494fa4.eps} \end{figure}$	Figure A.4: Opacity in models with different profiles of Z (constant, pZ1, pZ2 and pZ5 according to Fig. A.2) but located at the same point in the HR diagram.
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$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0494fa5.eps} \end{figure}$	Figure A.5: Comparison of the differential work $-{\rm d}W/{\rm d}\log T$ in models with different profiles of Z (constant, pZ1, pZ2 and pZ5 according to Fig. A.2) but located at the same point in the HR diagram.
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$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0494fb1.eps} \end{figure}$	Figure B.1: Iron accumulation profiles introduced in a 1.7 $M_\odot$ model.
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$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0494fb2.eps} \end{figure}$	Figure B.2: Opacity in a main sequence 1.7 $M_\odot$ model (labelled ``pFe'') including the iron accumulation profile displayed in Fig. B.1. For comparison the opacity of two others 1.7 $M_\odot$ models located at the same point in the HR diagram are also shown: the model labelled ``solar'' includes the AGS05 solar metal mixture, the pZ1 model is the one displayed in Fig. A.2.
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