ISOPHOT boosts dust masses in spiral galaxies

Abstract

We report photometry with ISO between 60 and 200 -um of six galaxies. Three of them are active and the extension of their spectra beyond the IRAS bands up to 200 -um confirms our previous conception that most of the dust there is warm and has a fairly uniform temperature of phantom {0}im30K. In the other three galaxies which are inactive, we detect a very cold component (phantom {0}im10K and less) that could hitherto at best be surmised. The most dramatic consequence is a threefold increase in the mass of interstellar material over what one would calculate without the ISO data. Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, the Netherlands and the United Kingdom) with the participation of ISAS and NASA.