Complex Organic Molecules at High Spatial Resolution Toward Orion-KL II:
  Kinematics
  It has recently been suggested that chemical processing can shape the spatial
distributions of complex molecules in the Orion-KL region and lead to the
nitrogen-oxygen "chemical differentiation" seen in previous observations of
this source. Orion-KL is a very dynamic region, and it is therefore also
possible that physical conditions can shape the molecular distributions in this
source. Only high spatial resolution observations can provide the information
needed to disentangle these effects. Here we present millimeter imaging studies
of Orion-KL at various beam sizes using the Combined Array for Research in
Millimeter-Wave Astronomy (CARMA). We compare molecular images with high
spatial resolution images that trace the temperature, continuum column density,
and kinematics of the source in order to investigate the effects of physical
conditions on molecular distributions. These observations were conducted at
\lambda = 3 mm and included transitions of ethyl cyanide [C2H5CN], methyl
formate [HCOOCH3], formic acid [HCOOH], acetone [(CH3)2CO], SiO, and methanol
[CH3OH]. We find differences in the molecular distributions as a function of
each of these factors. These results indicate that acetone may be produced by
chemical processing and is robust to large changes in physical conditions,
while formic acid is readily destroyed by gas-phase processing in warm and
dense regions. We also find that while the spatial distributions of ethyl
cyanide and methyl formate are not distinct as is suggested by the concept of
"chemical differentiation", local physical conditions shape the small-scale
emission structure for these species.
