All Figures

$\begin{figure} \par\includegraphics[width=17cm,clip]{2801f1.eps} \end{figure}$ Figure 1: NH₃ spectra of all comets ( left to right: C/2001 A2, 153P, C/2001 Q4, C/2002 T7) in the lowest 4 metastable levels, centered at zero velocity in the comet rest frame.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{2801f2.eps} \end{figure}$ Figure 2: OH radio line spectra recorded on 17 May 2004. Left: C/2001 Q4 (NEAT), 12 min integration time; Right: C/2002 T7 (LINEAR), 16 min integration time. The main beam brightness temperature $T_{{\rm MB}}$ is shown for the two OH lines at 1667 MHz ( upper) and 1665 MHz ( lower).
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{2801f3.eps} \end{figure}$ Figure 3: Predicted and observed MPIfR beam-averaged NH₃column densities for five comets. The thick part of the curves denote intervals where the declination enables observation at MPIfR ( $\delta > -25^{\circ }$ ). Maxima occur near closest approach to Earth. Points with standard deviations represent the line detections in C/1995 O1 (Hale-Bopp) (Bird et al. 1997); points without error bars are nondetection upper bounds for the Comets C/2001 A2-B, 153P, C/2001 Q4 and C/2002 T7. In all nondetection cases, the upper bounds are significantly less than the predictions based on an ammonia abundance of 1%. The shortfall is indicated in each case by the dotted line.
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In the text

$\begin{figure} \par\includegraphics[width=17cm,clip]{2801f1.eps} \end{figure}$	Figure 1: NH₃ spectra of all comets ( left to right: C/2001 A2, 153P, C/2001 Q4, C/2002 T7) in the lowest 4 metastable levels, centered at zero velocity in the comet rest frame.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{2801f2.eps} \end{figure}$	Figure 2: OH radio line spectra recorded on 17 May 2004. Left: C/2001 Q4 (NEAT), 12 min integration time; Right: C/2002 T7 (LINEAR), 16 min integration time. The main beam brightness temperature $T_{{\rm MB}}$ is shown for the two OH lines at 1667 MHz ( upper) and 1665 MHz ( lower).
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