All Figures

$\begin{figure}{\includegraphics[height=8.5cm, angle=-90]{1729fig1.eps} } \end{figure}$ Figure 1: Predicted CO line intensities, using different sets of calculated collisional rate coefficients, for an isothermal homogeneous sphere with a kinetic temperature 10 K, a H₂ density of 10³ cm^-3 and a CO column density of $3\times 10^{16}$ cm^-2. The line intensities are shown in relation to the values obtained using the CO-pH₂ rate coefficients from Flower (2001a). The upper rotational quantum number $J_{\rm {u}}$ is indicated on the x-axis. The rotational transitions are out of thermal equilibrium and, for transitions below $J=4\rightarrow 3$ , optically thick.
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In the text

$\begin{figure}{\includegraphics[width=16cm]{1729fig2.eps} } \end{figure}$ Figure 2: Calculated and extrapolated collisional de-excitation rate coefficients for CO in collisions with para-H₂. Open triangles indicate extrapolation in temperature to the rate coefficients of Flower & Launay (1985) (filled triangles). Open squares show the extrapolation to higher temperatures and energy levels of the recent rate coefficients calculated by Flower (2001a) (filled squares). For comparison the rate coefficients presented by Schinke et al. (1985) (filled circles) and the extrapolation performed by Larsson et al. (2002) (filled stars) are shown.
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In the text

$\begin{figure}{\includegraphics[height=8cm,angle=-90]{1729fig3.eps} } \end{figure}$ Figure 3: The solid lines are fits to the CO-p-H₂ collisional rate coefficients from Flower (2001a) (squares ) for transitions down to the ground state from upper energy levels $J_{\rm {u}}$ using a second order polynomial.
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In the text

$\begin{figure}\resizebox{8.8cm}{!}{\includegraphics{1729fig4.eps}} \par\end{figure}$ Figure 4: Collisional de-excitation rate coefficients for the lowest 50 states of SO₂ summed over all lower levels, calculated from the data by Green (1995) for various temperatures.
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In the text

$\begin{figure}\resizebox{8.8cm}{!}{\includegraphics{1729fig5.eps}} \end{figure}$ Figure 5: State-to-state de-excitation rate coefficients for SO₂ as fractions of the total downward rate coefficient (Fig. 4), as a function of the number of levels by which the transition is changed. The light (coloured) curves are values from Green (1995) at T=25 K for the 10th, 20th, 30th, 40th and 50th state above ground. The thick black curve is the normalized mean of the light (coloured) curves, adopted here to extrapolate Green's rate coefficients to higher-lying levels. The states are labelled in order of increasing energy.
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In the text

$\begin{figure}{\includegraphics[height=8cm,angle=-90]{1729fig3.eps} } \end{figure}$	Figure 3: The solid lines are fits to the CO-p-H₂ collisional rate coefficients from Flower (2001a) (squares ) for transitions down to the ground state from upper energy levels $J_{\rm {u}}$ using a second order polynomial.
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$\begin{figure}\resizebox{8.8cm}{!}{\includegraphics{1729fig4.eps}} \par\end{figure}$	Figure 4: Collisional de-excitation rate coefficients for the lowest 50 states of SO₂ summed over all lower levels, calculated from the data by Green (1995) for various temperatures.
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