| Description |
we propose to carry out isophot observations of a number of starless molecular cloud cores, which we have recently studied in a long-term jcmt observing programme. we discovered submillimetre continuum emission from myers starless cores for the first time. we now wish to observe these objects in the far-ir to obtain a complete picture of the spectral energy distributions (seds), and hence temperatures, luminosities, masses and natures of these cores which were not detected by iras. the peaks of the seds will tell us the temperatures of these cores, which may be the coldest star formation entities ever studied. our sources are ideally suited to study by isophot, since they are isolated regions, and have fwhm typically of 50 (see fig.1). on the basis of our submillimetre observations we hypothesised that these cores are pre-protostellar in nature, and at an earlier evolutionary stage than the class 0 protostar stage. we wish to obtain iso data to test our hypothesis, and furthermore iso presents a unique opportunity to test the specific predictions of models of ambipolar diffusion in low-mass star-forming regions such as these. the isophot observations will allow us to obtain luminosities for the sources, and thus to ascertain whether the cores are being internally heated by low luminosity protostars, or whether our hypothesis that the heating can be explained by the interstellar radiation field and cosmic rays is correct. in addition, when the isophot observations are combined with our existing submillimetre observations and our planned bolometer array observations, we will be able to test the detailed predictions of the different models of star formation and determine which, if any, is correct. for instance, our initial study has already shown that the power-law radial density profile of the standard model is incorrect. iso should allow us to say a great deal more about these cores. |
