Astronomy & Astrophysics

All Figures

$\begin{figure} \par\includegraphics[angle=-90,width=17.5cm,clip]{MS3981-f1.ps} \end{figure}$ Figure 1: CO(1-0) velocity-channel maps observed with the IRAM interferometer in the nucleus of NGC 7217 with a spatial resolution of (HPBW) $2.4\hbox {$^{\prime \prime }$ }\times 1.9\hbox {$^{\prime \prime }$ }$ (PA = 48 $^{\circ }$ ). The center of observations, given in Table 1, is indicated by a cross at $\alpha _{J2000}= 22^{\rm h}07^{\rm m}52.4^{\rm s}$ , $\delta _{J2000}= 31^\circ$ 21'32.2 $\hbox {$^{\prime \prime }$ }$ . Velocity-channels range from v=-145 km s^-1 to v=170 km s^-1 in steps of $5~{\rm km~s^{-1}}$ relative to V= 952 km s^-1 LSR (or 940 km s^-1 hel). The maps are corrected for primary beam attenuation. The contours begin at 10 mJy/beam, their spacing is 10 mJy/beam, and the maximum is 50 mJy/beam.
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In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{MS3981-f2.ps} \end{figure}$ Figure 2: Small maps of NGC 7217 made with the IRAM 30 m, with 7'' spacing, in CO(1-0) (bottom) and CO(2-1) (top). The velocity scale is -500 to $500~{\rm km~s^{-1}}$ relative to $V = 952~{\rm km~s^{-1}}$ LSR; the $T_{\rm A}^*$ temperature scale is from -.05 to 0.1 K (or $T_{\rm mb}$ from -.063 to 0.126 K for CO(1-0), and $T_{\rm mb}$ from -.088 to 0.175 K for CO(2-1)). Lack of time prevented to complete the raster in the NE position, but this does not significantly perturb the short-spacing correction.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{MS3981-f3.ps} \end{figure}$ Figure 3: CO(1-0) integrated intensity contours observed with the IRAM interferometer toward the center of NGC 7217 (the cross marks the coordinates of the center as given in Table 1, with offsets in arcseconds). The map has not been corrected for primary beam attenuation. The rms noise level is $\sigma =0.15$ Jy/beam km s^-1. Contour levels are from 5 $\sigma$ to 10 $\sigma$ with 1 $\sigma$ spacing. The beam of $2.4''\times 1.9''$ is plotted at the bottom left.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=7.7cm,clip]{MS3981-f4.ps} \end{figure}$ Figure 4: Radial distribution (azimuthal average, deprojected to face-on orientation) of the CO(1-0) integrated intensity, shown in Fig. 3. This shows the abrupt drop in intensity at the inner edge of the ring.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{MS3981-f5.ps} \end{figure}$ Figure 5: CO(2-1) integrated intensity map observed with the PdBI toward the center of NGC 7217 (the cross marks the coordinates of the center as given in Table 1, with offsets in arcseconds). The central CO(2-1) emission clump coincides with the actual galaxy center. The map has not been corrected for primary beam attenuation. The noise level is 0.3 Jy/beam km s^-1. Contours are from 3 $\sigma$ to 10 $\sigma$ , with 1 $\sigma$ spacing. The beam of $1.2'' \times 0.8''$ is plotted at the bottom left.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{MS3981-f6.ps} \end{figure}$ Figure 6: Overlay of the integrated intensity map of CO(1-0) (in gray scale) with the CO mean-velocity field, in contours spanning the range -150 km s^-1 to 150 km s^-1 in steps of 10 km s^-1. Velocities are referred to $V_{\rm hel}=952$ km s^-1. Solid (dashed) lines are used for positive (negative) velocities. The first solid contour represents systemic velocity.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=7.6cm,clip]{MS3981-f7.ps} \end{figure}$ Figure 7: CO(1-0) position-velocity (p-v)diagram along the major axis of NGC 7217 (East is to the right). The center is that of Table 1, and the velocity is relative to V = 952 km s^-1 LSR (or 940 km s^-1 hel). The markers with error bars show the H $\alpha$ radial velocities observed by B95.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.5cm,clip]{MS3981-f8.ps}\end{figure}$ Figure 8: Contours of the CO(1-0) map (same as Fig. 3), superposed with the greyscale CO(2-1) map tapered and convolved to identical resolution and corrected for primary beam attenuation, in Jy/beam km s^-1.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{MS3981-f9.ps}\end{figure}$ Figure 9: Contours and grey-scale of the CO(2-1)/CO(1-0) ratio map. The ratio is estimated only when the signals are larger than 3 $\sigma$ . Contours are from 0.2 to 1.2 by 0.1.
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In the text

$\begin{figure} \par\includegraphics[width=7.85cm,clip]{MS3981-f10a.ps}\par\vspace*{3.5mm} \includegraphics[width=7.85cm,clip]{MS3981-f10b.ps}\end{figure}$ Figure 10: Left: average CO spectra in the region of maximum emission in the center, covering a $2.4\hbox {$^{\prime \prime }$ }\times 1.9\hbox {$^{\prime \prime }$ }$ beam. top: CO(1-0), and bottom: CO(2-1). The dashed line indicates the 1 $\sigma$ level. Right: the spectra summed over the entire CO ring (excluding the center), top: CO(1-0), and bottom: CO(2-1).
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{MS3981-f11.ps} \end{figure}$ Figure 11: HST V - I (transformed from F606W-F814W) image with major- and minor-axis cuts superimposed. The positions of the rings are shown as a i) white cross = red dust CNR; ii) black cross = blue stellar CNR, H $\alpha$ ring; iii) white $\times$ = pseudo CNR; iv) black $\times$ = blue stellar inner ring. Darker pixels correspond to redder colors, and lighter pixels to bluer. The total horizontal size of this image is 67'' (North is up and East is left). Same color scale as in Fig. 12.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.6cm,clip]{MS3981-f12.ps} \end{figure}$ Figure 12: CO(1-0) low-resolution contours superposed on the HST V - I color image. Darker pixels correspond to redder colors, and lighter pixels to bluer.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.4cm,clip]{MS3981-f13.ps} \end{figure}$ Figure 13: CO(2-1) contours superposed on the HST V - I color image. As in Fig. 12, darker pixels mean redder colors. The CO(2-1) peaks exactly at the center of the nuclear bar/spiral feature.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{MS3981-f14.ps}\end{figure}$ Figure 14: Zoomed V - I image of center of NGC 7217 with continuum brightness peak (in both F606W and F814W) indicated with an open square. Darker pixels correspond to redder colors, and lighter to bluer ones. Axes are in arcsec. The center (0, 0) is now the galaxy center.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{MS3981-f15.ps}\end{figure}$ Figure 15: Surface brightness cuts taken along the slits shown in Fig. 11. The dotted line corresponds to F160W, the dashed line to I, and the solid line to V. In all panels, the various ring positions are shown by vertical dotted lines (from center: red dust ring, stellar ring, pseudo CNR, and inner stellar ring). In the lower panels, major-axis cuts are shown as solid lines and minor-axis cuts as dotted lines; horizontal dashed lines illustrate the colors of a 26 Myr stellar population reddened by 1.1 mag of extinction (see Sect. 5). The minor-axis cuts have been rectified by using an axial ratio of 0.8.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{MS3981-f16.ps}\end{figure}$ Figure 16: Contours of CO(1-0) emission (same as Fig. 3), superposed on the continuum subtracted H $\alpha$ +[NII] gray-scale map from Pogge (1989). Offsets are in arcseconds.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=6.8cm,clip]{MS3981-f17.ps}\end{figure}$ Figure 17: Rotation curve and derived frequencies $\Omega$ , $\Omega -\kappa /2$ and $\Omega +\kappa /2$ adopted for the simulations (Run A). The triangles are the H $\alpha$ rotational velocities; the squares are from the HI data (see B95).
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=17.3cm,clip]{MS3981-f18.ps}\end{figure}$ Figure 18: Left: gray scale plot of the stellar component distribution, in Run A (the gray scale is linear and axes are in kpc). Middle: gray scale plot of the corresponding gaseous component (the gray scale is logarithmic). Right: plot of the stars formed during the simulation (the gray scale is logarithmic).
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=17.5cm,clip]{MS3981-f19.ps}\end{figure}$ Figure 19: Same as Fig. 18, but zooming toward the center (the axes are in kpc).
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.5cm,clip]{MS3981-f20.ps}\end{figure}$ Figure 20: Evolution of the bar or oval distortion strength in Run A, estimated from the maximum Q₂ over radius of the ratio: m = 2 tangential force divided by the radial force.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.5cm,clip]{MS3981-f21.ps}\end{figure}$ Figure 21: Evolution in Run A of the pattern speed of the m=2 distortion. $\Omega _{\rm b}$ is estimated from the Fourier transform of the potential every 10 Myr, and in particular the evolution of the m=2 phase.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=8.5cm,clip]{MS3981-f22.ps}\end{figure}$ Figure 22: Star formation rate as a function of time for Run A. It is estimated as the percentage of the gas mass transformed into stars per Myr.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=17.3cm,clip]{MS3981-f23.ps.couleur}\end{figure}$ Figure 23: Left: gray scale plot of the stellar component distribution, in Run B (the gray scale is linear and axes are in kpc). Middle: gray scale plot of the corresponding gaseous component (the gray scale is logarithmic). Right: plot of the stars formed during the simulation (the gray scale is logarithmic).
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=7.7cm,clip]{MS3981-f4.ps} \end{figure}$	Figure 4: Radial distribution (azimuthal average, deprojected to face-on orientation) of the CO(1-0) integrated intensity, shown in Fig. 3. This shows the abrupt drop in intensity at the inner edge of the ring.
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$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{MS3981-f6.ps} \end{figure}$	Figure 6: Overlay of the integrated intensity map of CO(1-0) (in gray scale) with the CO mean-velocity field, in contours spanning the range -150 km s^-1 to 150 km s^-1 in steps of 10 km s^-1. Velocities are referred to $V_{\rm hel}=952$ km s^-1. Solid (dashed) lines are used for positive (negative) velocities. The first solid contour represents systemic velocity.
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$\begin{figure} \par\includegraphics[angle=-90,width=7.6cm,clip]{MS3981-f7.ps} \end{figure}$	Figure 7: CO(1-0) position-velocity (p-v)diagram along the major axis of NGC 7217 (East is to the right). The center is that of Table 1, and the velocity is relative to V = 952 km s^-1 LSR (or 940 km s^-1 hel). The markers with error bars show the H $\alpha$ radial velocities observed by B95.
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$\begin{figure} \par\includegraphics[angle=-90,width=8.5cm,clip]{MS3981-f8.ps}\end{figure}$	Figure 8: Contours of the CO(1-0) map (same as Fig. 3), superposed with the greyscale CO(2-1) map tapered and convolved to identical resolution and corrected for primary beam attenuation, in Jy/beam km s^-1.
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$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{MS3981-f9.ps}\end{figure}$	Figure 9: Contours and grey-scale of the CO(2-1)/CO(1-0) ratio map. The ratio is estimated only when the signals are larger than 3 $\sigma$ . Contours are from 0.2 to 1.2 by 0.1.
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$\begin{figure} \par\includegraphics[width=7.85cm,clip]{MS3981-f10a.ps}\par\vspace*{3.5mm} \includegraphics[width=7.85cm,clip]{MS3981-f10b.ps}\end{figure}$	Figure 10: Left: average CO spectra in the region of maximum emission in the center, covering a $2.4\hbox {$^{\prime \prime }$ }\times 1.9\hbox {$^{\prime \prime }$ }$ beam. top: CO(1-0), and bottom: CO(2-1). The dashed line indicates the 1 $\sigma$ level. Right: the spectra summed over the entire CO ring (excluding the center), top: CO(1-0), and bottom: CO(2-1).
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$\begin{figure} \par\includegraphics[angle=-90,width=8.6cm,clip]{MS3981-f12.ps} \end{figure}$	Figure 12: CO(1-0) low-resolution contours superposed on the HST V - I color image. Darker pixels correspond to redder colors, and lighter pixels to bluer.
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$\begin{figure} \par\includegraphics[angle=-90,width=8.4cm,clip]{MS3981-f13.ps} \end{figure}$	Figure 13: CO(2-1) contours superposed on the HST V - I color image. As in Fig. 12, darker pixels mean redder colors. The CO(2-1) peaks exactly at the center of the nuclear bar/spiral feature.
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$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{MS3981-f14.ps}\end{figure}$	Figure 14: Zoomed V - I image of center of NGC 7217 with continuum brightness peak (in both F606W and F814W) indicated with an open square. Darker pixels correspond to redder colors, and lighter to bluer ones. Axes are in arcsec. The center (0, 0) is now the galaxy center.
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$\begin{figure} \par\includegraphics[angle=-90,width=8.8cm,clip]{MS3981-f16.ps}\end{figure}$	Figure 16: Contours of CO(1-0) emission (same as Fig. 3), superposed on the continuum subtracted H $\alpha$ +[NII] gray-scale map from Pogge (1989). Offsets are in arcseconds.
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$\begin{figure} \par\includegraphics[angle=-90,width=6.8cm,clip]{MS3981-f17.ps}\end{figure}$	Figure 17: Rotation curve and derived frequencies $\Omega$ , $\Omega -\kappa /2$ and $\Omega +\kappa /2$ adopted for the simulations (Run A). The triangles are the H $\alpha$ rotational velocities; the squares are from the HI data (see B95).
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$\begin{figure} \par\includegraphics[angle=-90,width=17.3cm,clip]{MS3981-f18.ps}\end{figure}$	Figure 18: Left: gray scale plot of the stellar component distribution, in Run A (the gray scale is linear and axes are in kpc). Middle: gray scale plot of the corresponding gaseous component (the gray scale is logarithmic). Right: plot of the stars formed during the simulation (the gray scale is logarithmic).
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$\begin{figure} \par\includegraphics[angle=-90,width=17.5cm,clip]{MS3981-f19.ps}\end{figure}$	Figure 19: Same as Fig. 18, but zooming toward the center (the axes are in kpc).
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$\begin{figure} \par\includegraphics[angle=-90,width=8.5cm,clip]{MS3981-f20.ps}\end{figure}$	Figure 20: Evolution of the bar or oval distortion strength in Run A, estimated from the maximum Q₂ over radius of the ratio: m = 2 tangential force divided by the radial force.
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$\begin{figure} \par\includegraphics[angle=-90,width=8.5cm,clip]{MS3981-f21.ps}\end{figure}$	Figure 21: Evolution in Run A of the pattern speed of the m=2 distortion. $\Omega _{\rm b}$ is estimated from the Fourier transform of the potential every 10 Myr, and in particular the evolution of the m=2 phase.
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$\begin{figure} \par\includegraphics[angle=-90,width=8.5cm,clip]{MS3981-f22.ps}\end{figure}$	Figure 22: Star formation rate as a function of time for Run A. It is estimated as the percentage of the gas mass transformed into stars per Myr.
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$\begin{figure} \par\includegraphics[angle=-90,width=17.3cm,clip]{MS3981-f23.ps.couleur}\end{figure}$	Figure 23: Left: gray scale plot of the stellar component distribution, in Run B (the gray scale is linear and axes are in kpc). Middle: gray scale plot of the corresponding gaseous component (the gray scale is logarithmic). Right: plot of the stars formed during the simulation (the gray scale is logarithmic).
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