Tracing the Mass during Low-Mass Star Formation, IV: Observations and Modeling of the Submillimeter Continuum Emission from Class I Protostars

摘要

We present results from the observations and modeling of seventeen Class Icores with the Submillimetre Common Users Bolometer Array (SCUBA) on the JamesClerk Maxwell Telescope (JCMT). By modeling the transfer of radiation throughthe envelope for nine cores, we find, for a power law distributionn(r)=n_f(r/r_f)^-p, the average and standard deviation p=1.6 +/- 0.4 and amedian of p=1.8. However, the inclusion of a disk or other point-like componentcan cause the derived p to be shallower by as much as 0.5. In addition, we testthe Shu collapse model for our sources and discuss the application of simpleranalyses that derive a density power law distribution directly from the slopeof the intensity radial profile. The total mass of the envelope in our samplehas a range from 0.04 to 5.0 M_sun, but these masses disagree with the virialmasses derived from molecular line observations. Finally, we discuss the natureof these sources in light of various evolutionary indicators and find thatT_bol and L_obs/L_smm are often inconsistent in distinguishing Class 0 fromClass I cores.