Submillimeter Continuum Observations of rho Ophiuchi A: The Candidate Protostar VLA 1623 and Prestellar Clumps

We have mapped the submillimeter continuum emission from the rich star-forming core, ρ Oph A, at 350, 450, 800, and 1300 μm using the JCMT and IRAM 30 m telescopes. In addition to the diffuse emission from the cloud core itself, these observations reveal four well-defined clumps, which, suprisingly, are barely visible in the single-dish molecular maps obtained so far in this region. The gas may have partially frozen out onto the dust grains, due to low temperature and/or high density in the clumps. We discuss the possibility that these clumps are prestellar or extremely young, low-mass protostars