All Figures

$\begin{figure} \par\includegraphics[width=15.3cm,clip]{7236fig1.eps} \end{figure}$ Figure 1: Three colour composite image of SFO 75 and its associated HII region, RCW 98. The position of the IRAS point source and ionising star are indicated by a black and white cross. This composite image has been produced using a combination of the DSS red band optical image, SuperCOSMOS H $_{\alpha }$ image and GLIMPSE 8 ${\mu }$ m image which are coloured red, blue and green respectively.
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In the text

$\begin{figure} \par\includegraphics[width=9.2cm, trim=0 50 0 20]{7236fig2a.eps}\includegraphics[width=9.2cm, trim= 0 0 0 0]{7236fig2b.eps}\par \par\end{figure}$ Figure 2: Left panel: large scale 8 ${\mu }$ m GLIMPSE image of SFO 75 and its associated HII region, RCW 98. The position of the IRAS point source and ionising star are indicated by a white cross. At 8 ${\mu }$ m the emission is dominated by PAH emission that are found in photo-dissociation region and marks the interface between the ionised gas within the HII region and the surrounding molecular gas. Right panels: observational results laid over the region of the 8 ${\mu }$ m GLIMPSE image outlined in white in the left panel. Clockwise from the top left panel: 1.3 cm radio continuum, integrated ¹³CO emission, integrated ammonia (1, 1) emission (main line) and the 1.2 mm continuum emission. The position of the IRAS point source is indicated by a white cross and its positional uncertainty by a black ellipse. The respective beam shape of each telescope is shown to size in the lower left corner of each plot. Additionally, in the image showing the ¹³CO emission we have plotted a dashed line to indicate the cut through the cloud used to produce the position-velocity diagram presented in Fig. 3. The integrated ¹³CO and ammonia emission has been integrated between -32 and -40 km s^-1, and -34.5 and -40 km s^-1 velocity ranges respectively. The contour levels used in the image are as follows: 1.3 cm radio contours begin at 3 $\sigma$ and increase in steps of 2 $\sigma$ where $\sigma = 2.5$ mJy; ¹³CO contours begin at 4 $\sigma$ and increase in steps of 3 $\sigma$ where $\sigma = 9$ K km s^-1; 1.2 mm contour levels are 0.1, 0.2, 0.4, 0.7, 1.1 and 1.6 Jy; ammonia contours begin at 4 $\sigma$ and increase in steps of 3 $\sigma$ where $\sigma = 80$ mJy km s^-1.
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In the text

$\begin{figure} \par\includegraphics[width=5.7cm,clip]{7236fig3.eps} \end{figure}$ Figure 3: Position-velocity diagram taken through the ionising star-CO core vector as indicated in Fig. 2. The direction of ionisation is from right to left. This diagram clearly reveals the presence of blue and red shifted emission at the front of the molecular cloud, indicative of shocks and the steep emission gradient consistent with compression of the cloud by the ionisation front. The contours start at 20% and increase in steps of 10% of the peak value (11.1 K km s^-1).
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In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{7236fig4.eps} \end{figure}$ Figure 4: Spectral energy distribution of SFO 75. Results of a two component greybody fit to the IRAS and 1.2 mm dust continuum emission.
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In the text

$\begin{figure} \par\includegraphics[width=18cm,clip]{7236fig5.eps} \end{figure}$ Figure 5: Velocity channel maps of the ammonia (1, 1) main line emission contoured over an enlarged region of 8 ${\mu }$ m image presented in Fig. 2 (highlighted white square in lower right image). The central velocities are indicated in the top right corners of each map and are 0.6 km s^-1 thick. The position of the IRAS point source and its associated error are indicated by a cross and ellipse respectively. The first contour starts at 4 $\sigma$ and increase in steps of 4 $\sigma$ . The size of the synthesised beam is shown to scale in the lower left corner.
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In the text

$\begin{figure} \par\includegraphics[width=9cm,clip]{7236fig6.eps} \end{figure}$ Figure 6: Spatially integrated spectral line profiles for Core A and Core B. The vertical dashed-dotted line indicated the velocity of the ¹³CO core.
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In the text

$\begin{figure} \par\includegraphics[width=7.7cm,clip]{7236fig7a.eps}\hspace*{4mm} \includegraphics[width=7.7cm,clip]{7236fig7b.eps} \end{figure}$ Figure 7: 2MASS and GLIMPSE three colour composite images. Left panel: 2MASS composite produced by combining J, H and $K_{\rm {s}}$ band images which are shown in blue, green and red respectively. This image is overlaid with contours of the GLIMPSE 8 ${\mu }$ m emission and the integrated NH₃ emission in orange and blue respectively. Right panel: GLIMPSE composite made from the 3.6, 4.5 and 5.8 ${\mu }$ m band images which are coloured blue, green and red respectively. The positions of the 2MASS sources in both images are identified by the reference given in Table 5.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{7236fig8.eps} \end{figure}$ Figure 8: 2MASS $K_{\rm {s}}$ versus J- $K_{\rm {s}}$ magnitude-colour diagram of the objects detected towards Core A. The thick black line shows $K_{\rm {s}}$ magnitudes of main sequence stars located at a distance of 2.8 kpc, taken from Martins & Plez (2006) and Schmidt-Kaler (1982), and assuming zero visual extinction along the line of sight. The dotted lines correspond to a visual extinction of 30 mag, which have been calculated using the standard extinction law of Mathis (1990) with $R_{\rm {v}}=3.1$ .
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In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{7236fig4.eps} \end{figure}$	Figure 4: Spectral energy distribution of SFO 75. Results of a two component greybody fit to the IRAS and 1.2 mm dust continuum emission.
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$\begin{figure} \par\includegraphics[width=9cm,clip]{7236fig6.eps} \end{figure}$	Figure 6: Spatially integrated spectral line profiles for Core A and Core B. The vertical dashed-dotted line indicated the velocity of the ¹³CO core.
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