ISO STUDY OF PROTOSTARS

> 4542s grade 3 time, for which we ask for an upgrade > is to be transferred from rchini.prostata a multiwavelength isophot study is proposed to measure the ir energy distributions of a sample of protostar candidates. during a recent groundbased survey at the iram 30m, sest and jcmt, we have discovered a number of so far unknown sources of strong mm emission. because none of the sources has been detected by iras, they are the coldest and densest dust condensations ever found. the proposed isophot measurements will be combined with our existing mm/submm photometry in order to determine temperature, luminosity, mass, and evolutionary status of these young objects. microscanning with isocam will be performed to reveal possible embedded stellar sources. so far one of our targets (circinusmms) has been observed with isocam and isophot and was detected in all bands. interestingly, the spectral energy distribution increases until 200 mic, suggesting the presence of a large amount of cold (t<15k) dust. our model fits to the entire sed indicate that the heating is provided by an internal source. this example demonstrates that our sample consists of true cold protostellar objects and justifies the followup observations for the remaining targets. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]