All Figures

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F1.epsi} \end{figure}$ Figure 1: Raster scan positions for the LWS beam in a $0.5^{\circ } \times 0.5^{\circ }$ view centered on ${\rm RA} (2000) = 21^{{\rm h}}53^{{\rm m}}33^{{\rm s}}, \delta (2000) = 47^{\circ }16'18''$ . North is up and RA increases to the left.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F2.vps.epsi} \end{figure}$ Figure 2: Blister ionization boundaries for H⁰/H⁺, He⁰/He⁺, C⁺/C⁺⁺, and the H₂/H⁰ photo-dissociation boundary. The heavy solid line shows the "evacuated'' region around the ionizing star. Also shown are the total density contours for 100, 250, 500, and 1000 cm^-3, as well as 4 lines of sight for the positions shown in Fig. 1.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F3.epsi} \end{figure}$ Figure 3: The absorption cross section for the PDR dust and the dust in the HII region as assumed in the model. The dotted curve (DL dust) shows the absorption for a recent model that includes PAH-type dust (Weingartner & Draine 2001a; Li & Draine 2001).
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F4.epsi} \end{figure}$ Figure 4: The gas temperature in the PDR as a function of the visual extinction. Upper panel: the PDR boundary temperature is assumed to be 500 K independent of direction from the central star; all lines of sight fall between the two curves shown for positions N and R. Lower panel: the PDR boundary temperature is assumed to vary with angle as shown; such a variation gives a spatial profile for the fine- structure lines in much better agreement with the observations.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F5.epsi} \end{figure}$ Figure 5: Far-infrared line ratios as functions of temperature and hydrogen density in a semi-infinite, uniform slab for three values of the [OI] 63 $\mu$ m optical depth, considering only excitation by atomic hydrogen. The abundance ratio O/C = 2. For clarity, only the upper panel has the grid values of temperature and density indicated.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F6.epsi} \end{figure}$ Figure 6: Line emissivities in erg cm^-3 s^-1 for the fine structure lines along the N (upper panel) and P (lower panel) lines of sight. Positive distance is into the blister (increasing density). For clarity the CII line emissivity is decreased by 2 and 3 orders of magnitude for positions N and P, respectively.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F7.epsi} \end{figure}$ Figure 7: Observed and calculated line intensities (erg cm^-2 s^-1 sr^-1) for the [OI] 63 $\mu$ m line; upper panel for the scan positions J - R; lower panel for the scan positions A - I of Fig. 1. The upper and lower solid lines show the calculated values for the full model (constant boundary temperature) and the HII region only. The dashed curves show the calculated values with an assumed variation for the neutral gas boundary temperature (cf. Sect. 5).
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F8.epsi} \end{figure}$ Figure 8: Observed and calculated line intensities for the [OI] 146 $\mu$ m line; upper panel for the scan positions J - R; lower panel for the scan positions A - I of Fig. 1. Curves and units as in Fig. 7.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F9.epsi} \end{figure}$ Figure 9: Observed and calculated line intensities for the [CII] 158 $\mu$ m line; upper panel for the scan positions J - R; lower panel for the scan positions A - I of Fig. 1. Curves and units as in Fig. 7.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F1.epsi} \end{figure}$	Figure 1: Raster scan positions for the LWS beam in a $0.5^{\circ } \times 0.5^{\circ }$ view centered on ${\rm RA} (2000) = 21^{{\rm h}}53^{{\rm m}}33^{{\rm s}}, \delta (2000) = 47^{\circ }16'18''$ . North is up and RA increases to the left.
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F2.vps.epsi} \end{figure}$	Figure 2: Blister ionization boundaries for H⁰/H⁺, He⁰/He⁺, C⁺/C⁺⁺, and the H₂/H⁰ photo-dissociation boundary. The heavy solid line shows the "evacuated'' region around the ionizing star. Also shown are the total density contours for 100, 250, 500, and 1000 cm^-3, as well as 4 lines of sight for the positions shown in Fig. 1.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F3.epsi} \end{figure}$	Figure 3: The absorption cross section for the PDR dust and the dust in the HII region as assumed in the model. The dotted curve (DL dust) shows the absorption for a recent model that includes PAH-type dust (Weingartner & Draine 2001a; Li & Draine 2001).
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F5.epsi} \end{figure}$	Figure 5: Far-infrared line ratios as functions of temperature and hydrogen density in a semi-infinite, uniform slab for three values of the [OI] 63 $\mu$ m optical depth, considering only excitation by atomic hydrogen. The abundance ratio O/C = 2. For clarity, only the upper panel has the grid values of temperature and density indicated.
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F6.epsi} \end{figure}$	Figure 6: Line emissivities in erg cm^-3 s^-1 for the fine structure lines along the N (upper panel) and P (lower panel) lines of sight. Positive distance is into the blister (increasing density). For clarity the CII line emissivity is decreased by 2 and 3 orders of magnitude for positions N and P, respectively.
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F8.epsi} \end{figure}$	Figure 8: Observed and calculated line intensities for the [OI] 146 $\mu$ m line; upper panel for the scan positions J - R; lower panel for the scan positions A - I of Fig. 1. Curves and units as in Fig. 7.
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$\begin{figure} \par\includegraphics[width=8.8cm,clip]{H4401F9.epsi} \end{figure}$	Figure 9: Observed and calculated line intensities for the [CII] 158 $\mu$ m line; upper panel for the scan positions J - R; lower panel for the scan positions A - I of Fig. 1. Curves and units as in Fig. 7.
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