Observations of cold dust in young supernova remnants

The importance of supernovae as a source of interstellar dust has long been debated. Theoretical models predict that the final event in the life of a massive star (10--30 Modot) should produce 0.3--5Modot of dust. If this were true, then TypeII supernovae would be significant contributors to the ISM dust budget. In the early universe, this is particularly important, as the other major sources of dust (low-intermediate mass AGB stars) do not evolve on a short enough time-scale to produce the quantities of dust now observed at high redshift in the deep submm populations and QSOs. However, observational evidence for such quantities of dust are rather lacking. IRAS and ISO studies of the youngest Galactic supernova remnants detect masses of dust which are > 3 orders of magnitude smaller than predicted by the models. Higher condensation efficiencies have been attributed to SN1987A from the fading of the silicate line, however the high efficiency relies critically on assumptions about the clumpiness of the dust, and there have been no direct measurements of significant dust masses in young supernova remnants until now. Here, we present SCUBA images of a young Galactic supernova remnant at 850 and 450 microns, which show that of order a few solar masses of dust have been produced in the supernovae, or by the massive star progenitor just prior to the explosion