Radio Imaging of the NGC 1333 IRAS 4B Region
  The NGC 1333 IRAS 4B region was observed in the 6.9 mm and 1.3 cm continuum
with an angular resolution of about 0.4 arcseconds. IRAS 4BI was detected in
both bands, and BII was detected in the 6.9 mm continuum only. The 1.3 cm
source of BI seems to be a disk-like flattened structure with a size of about
50 AU. IRAS 4BI does not show any sign of multiplicity. Examinations of
archival infrared images show that the dominating emission feature in this
region is a bright peak in the southern outflow driven by BI, corresponding to
the molecular hydrogen emission source HL 9a. Both BI and BII are undetectable
in the mid-IR bands. The upper limit on the far-IR flux of IRAS 4BII suggests
that it may be a very low luminosity young stellar object.
