Intermediate-mass hot cores at 500 AU: disks or outflows?
  Observations with the Plateau de Bure Interferometer in the most extended
configuration toward two intermediate-mass star-forming regions, IRAS22198+6336
and AFGL5142, reveal the presence of several complex organic molecules at ~500
AU scales, confirming the presence of hot cores in both regions. The hot cores
are not rich in CN-bearing molecules, as often seen in massive hot cores, and
are mainly traced by CH3CH2OH, (CH2OH)2, CH3COCH3, and CH3OH, with additionally
CH3CHO, CH3OD and HCOOD for IRAS22198+6336, and C6H, and O13CS for AFGL5142.
The emission of complex molecules is resolved down to sizes of ~300 and ~600
AU, for IRAS22198+6336 and AFGL5142, respectively, and most likely is tracing
protostellar disks rather than flattened envelopes or toroids as usually found.
This is specially clear for the case of IRAS22198+6336, where we detect a
velocity gradient for all the mapped molecules perpendicular to the most
chemically rich outflow of the region, yielding a dynamic mass >4 Msun. As for
AFGL5142, the hot core emission is resolved into two elongated cores separated
1800 AU. A detailed comparison of the complex molecule peaks to the new CO(2-1)
data and H2O maser data from literature suggests that also for AFGL5142 the
complex molecules are mainly associated with disks, except for a faint and
extended molecular emission found to the west, which is possibly produced in
the interface between one of the outflows and the dense surrounding gas.
