A search for co-evolving ion and neutral gas species in prestellar
  molecular cloud cores
  Comparison of linewidths of spectral line profiles of ions and neutral
molecules have been recently used to estimate the strength of the magnetic
field in turbulent star-forming regions. However, the ion (HCO+) and neutral
(HCN) species used in such studies may not be necessarily co-evolving at every
scale and density and may thus not trace the same regions. Here, we use coupled
chemical/dynamical models of evolving prestellar molecular cloud cores
including non-equilibrium chemistry, with and without magnetic fields, to study
the spatial distribution of HCO+ and HCN, which have been used in observations
of spectral linewidth differences to date. In addition, we seek new ion-neutral
pairs that are good candidates for such observations because they have similar
evolution and are approximately co-spatial in our models. We identify three
such good candidate pairs: HCO+/NO, HCO+/CO, and NO+/NO.
