All Figures

$\begin{figure} \par\epsfig{figure=0438fig1a.ps,width=8cm,clip=}\vspace*{1cm} \epsfig{figure=0438fig1b.ps,width=8cm,clip=}\end{figure}$ Figure 1: NGC 4013 ( top) and NGC 5907 ( bottom) observed in the $850~{\mu}$ m continuum with SCUBA. Both the background image and the contours refer to emission at $850~{\mu}$ m. For NGC 4013 the contour levels are at 10.0, 10.4, 11.4, 13.3 15.9, 19.2, 23.3, 28.1, 33.7 and 40.0 mJy/16'' beam while for NGC 5907 the contour levels are at 20.0, 20.8, 23.4, 27.8, 33.8, 41.6, 51.1, 62.3, 75.3 and 90.0 mJy/16'' beam. In both cases the first contour level is at the 3 $\sigma$ level and the beam size is 16''( FWHM). Coordinates are in epoch 2000.
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In the text

$\begin{figure} \par\epsfig{figure=0438fig2.ps,width=8.8cm,angle=0,clip=}\end{figure}$ Figure 2: Radiation transfer modelling of NGC 4565 in the V-band. The real galaxy, as observed by Howk & Savage (1999), is shown at the top whilst the corresponding image generated by our radiation transfer simulation is situated at the bottom.
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In the text

$\begin{figure} \par\epsfig{figure=0438fig3a.eps,width=8.6cm,clip=}\vspace*{3mm} ... ...,clip=}\vspace*{3mm} \epsfig{figure=0438fig3c.eps,width=8.6cm,clip=}\end{figure}$ Figure 3: Flux densities for NGC 4013, NGC 5907 and NGC 4565 as observed by IRAS (60 and $100~{\mu}$ m), SCUBA (450 and $850~{\mu}$ m) and IRAM (1.2 mm). In each case, the thermal spectrum has been fitted by the sum of a warm and cold dust component (dashed and dotted lines respectively). The total SED is given by the solid curve. The proportion of dust in each of the warm and cold components, as well as their associated temperatures, are given in Table 3.
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In the text

$\begin{figure} \par\epsfig{figure=0438fig4a.eps,width=8.6cm,clip=}\vspace*{5mm} ... ...,clip=}\vspace*{5mm} \epsfig{figure=0438fig4c.eps,width=8.6cm,clip=}\end{figure}$ Figure 4: Major axis profiles of NGC 4013, NGC 5907 and NGC 4565 in $850~{\mu}$ m and 1.2 mm surface brightness (solid line, left axis) and visual optical depth (dashed line, right axis). The latter has been inferred from radiation transfer modelling and the map in visual optical depth has been smoothed to the corresponding spatial resolution of the submm/mm data before profiling (16'' and 20'' at $850~{\mu}$ m and 1.2 mm respectively). The major axis is defined such that positive values correspond to north-east, south-east and north-west for NGC 4013, NGC 5907 and NGC 4565 respectively.
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In the text

$\begin{figure} \par\epsfig{figure=0438fig5.eps,width=11cm,clip=}\end{figure}$ Figure 5: Emissivity $Q(\lambda )$ of astrophysical dust in the far-infrared, submm and millimeter wavebands. The plot depicts the values collated in Table 4 employing identical markers for similar astrophysical environments. The estimates that we derive for NGC 4013, NGC 4565, NGC 5907 and NGC 891 (the latter in Alton et al. 2000) have been attributed to dust residing in molecular gas clouds (solid circles). The dashed and dotted lines correspond to a wavelength dependency for the emissivity which varies as $\beta =2.0$ and $\beta =1.5$ respectively ( $Q \propto \lambda ^{-{\beta }}$ ). The lines have been set to pass arbitrarily through the frequently-cited model value of Draine & Lee (1984) at $250~\mu$ m.
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In the text

$\begin{figure} \par\epsfig{figure=0438fig6a.eps,width=8.2cm,clip=}\vspace*{3mm} \epsfig{figure=0438fig6b.eps,width=8.2cm,clip=}\end{figure}$ Figure 6: Dust and neutral gas profiles along the major axis of NGC 4013 and NGC 5907. The solid circles denote the distribution of grains (using multiplicative factors of 500 and 350 to clarify the plot). The open circles and open squares trace the respective distributions of molecular and atomic gas within the disk. The major axis is defined such that positive values correspond to north-east and south-east for NGC 4013 and NGC 5907 respectively
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In the text

$\begin{figure} \par\epsfig{figure=0438fig7a.eps,width=8.2cm,clip=}\par\epsfig{figure=0438fig7b.eps,width=8.2cm,clip=}\end{figure}$ Figure 7: The gas-to-dust ratio along the major axes of NGC 4013 and NGC 5907. The CO line has been converted to a H₂ column density assuming $X= 2 \times 10^{20}$ cm^-2 K km s^-1. The dust column density follows from the submm emissivities derived in Sect. 6 of this work.
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In the text

$\begin{figure} \par\epsfig{figure=0438fig2.ps,width=8.8cm,angle=0,clip=}\end{figure}$	Figure 2: Radiation transfer modelling of NGC 4565 in the V-band. The real galaxy, as observed by Howk & Savage (1999), is shown at the top whilst the corresponding image generated by our radiation transfer simulation is situated at the bottom.
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$\begin{figure} \par\epsfig{figure=0438fig7a.eps,width=8.2cm,clip=}\par\epsfig{figure=0438fig7b.eps,width=8.2cm,clip=}\end{figure}$	Figure 7: The gas-to-dust ratio along the major axes of NGC 4013 and NGC 5907. The CO line has been converted to a H₂ column density assuming $X= 2 \times 10^{20}$ cm^-2 K km s^-1. The dust column density follows from the submm emissivities derived in Sect. 6 of this work.
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