Shocked water in the Cep E protostellar outflow
  Previous far-infrared observations at low-angular resolution have reported
the presence of water associated with low-velocity outflow shocks and
protostellar envelopes. The outflow driven by the intermediate-mass class 0
protostar Cep E is among the most luminous outflows detected so far. Using the
IRAM 30m telescope, we searched for and detected the para-water line emission
at 183 GHz in the Cep E star-forming core. The emission arises from
high-velocity gas close to the protostar, which is unresolved in the main beam
of the telescope. Complementary observations at 2" resolution with the Plateau
de Bure interferometer helped establish the origin of the emission detected and
the physical conditions in the emitting gas. The water line profile and its
spatial distribution are very similar to those of SiO. We find that the water
emission arises from warm ($\sim 200\K$), dense ($(1-2)\times 10^6\cmmt$) gas,
and its abundance is enhanced by one to two orders of magnitude with respect to
the protostellar envelope. We detect water emission in strong shocks from the
high-velocity jet at 1000 AU from the protostar. Despite the large beam size of
the telescope, such emission should be detectable with Herschel.
