ALMA Images of the Orion Hot Core at 349 GHz
  We present ALMA images of the dust and molecular line emission in the Orion
Hot Core at 349 GHz. At 0.2" angular resolution the images reveal multiple
clumps in an arc ~ 1" east of Orion Source I, the protostar at the center of
the Kleinmann-Low Nebula, and another chain of peaks from IRc7 towards the
southwest. The molecular line images show narrow filamentary structures at
velocities > 10 km/s away from the heavily resolved ambient cloud velocity ~5
km/s. Many of these filaments trace the SiO outflow from Source I, and lie
along the edges of the dust emission. Molecular line emission at excitation
temperatures 300--2000 K, and velocities > 10 km/s from the ambient cloud,
suggest that the Hot Core may be heated in shocks by the outflow from Source I
or from the BN/Source I explosion. The spectral line observations also reveal a
remarkable molecular ring, ~ 2" south of Source I, with a diameter ~ 600 AU.
The ring is seen in high excitation transitions of HC3N, HCN v2=1, and SO2. An
impact of ejecta from the BN/Source I explosion with a dense dust clump could
result in the observed ring of shocked material.
