Cold dust in nearby galaxies: implications for observing the high-redshiftuniverse

The distribution of dust in nearby spiral galaxies not only affects our per ceptions of disc morphology but will both redden and extinguish our view of the more distant Universe. In this paper, we present remarkable evidence f or a population of cold grains (15-20 K) which is ten times more massive th an the dust detected by IRAS and extends at least 50% beyond the present-da y stellar disc. This conclusion is based chiefly on recent imaging observat ions carried out with the far-infrared/submillimetre arrays ISOPHOT and SCU BA. Our initial inference for visibility of the high-redshift Universe is t hat 40% of the light emitted at z = 2 fails to reach the present-day observ er due to intervening, foreground spirals.