Radiative hydrodynamical models of protostellar collapse are used to calculate the spectral energy distributions of single and binary protostars at the phase of formation of the first (outer) protostellar core. In accordance with the established nomenclature, where classes 0, I, II, and III form a sequence in time, we term these pre-class 0 objects to be class-I ('class minus one') objects. These class -I objects are characterized by central core temperatures of approximately 200 K, envelope temperatures of approximately 10 K, and substantial far-infrared and submillimeter-wave fluxes. While undetectable by IRAS, these objects should be detectable by Infrared Space Observatory (ISO) and Space Infrared Telescope Facility (SITF) at 60 micrometer and longer wavelengths. First protostellar cores exist for times on the order of a few percent of the total collapse time, implying that a small fraction of all protostellar objects should be class -I objects.
No takes yet. Share an insight, caveat, or question.
Boss et al. (1995) studied this question.