Deciphering the 3-D Orion Nebula-II: A low-ionization region of multiple
  velocity components southwest of Theta1OriC confounds interpretation of low
  velocity resolution studies of temperature, density, and abundance
  We establish that there are two velocity systems along lines-of-sight that
contribute to the emission-line spectrum of the the brightest parts of the
Orion Nebula. These overlie the Orion-S embedded molecular cloud southwest of
the dominant ionizing star (Theta1OriC). Examination of 10x10" samples of high
spectral resolution emission-line spectra of this region reveals it to be of
low ionization, with velocities and ionization different from the central part
of the Nebula. These properties jeopardize earlier determinations of abundance
and physical conditions since they indicate that this region is much more
complex than has been assumed in analyzing earlier spectroscopic studies and
argue for use of very high spectral resolution or known simple regions in
future studies.
