Interferometric observations of nitrogen-bearing molecular species in
  the star-forming core ahead of HH 80N
  We present VLA NH3 and PdBI NH2D and H13NC observations of the star forming
core ahead of HH 80N, the optically obscured northern counterpart of the
Herbig-Haro objects HH 80/81. The main goal is to determine the kinematical
information of the high density regions of the core ($n\lesssim 10^5$
cm$^{-3}$), missed in previous works due to the depletion of the species
observed (e.g. CS). The obtained maps show different kinematical signatures
between the eastern and western parts of the core, suggesting a possible
dynamical interaction of the core with the HH 80/81/80N outflow. The analysis
of the Position-Velocity (PV) plots of these species rules out a previous
interpretation of having a molecular ring-like structure of $6\times 10^4$ AU
of radius traced by CS infalling onto a central protostar found in the core
(IRS1). High degree of deuteration, with respect to the central part of the
core harboring IRS1, is derived in the eastern part, where a dust condensation
(SE) is located. This deuteration trend of NH3 suggests that SE is in a
prestellar evolutionary stage, earlier than that of the IRS1. Since SE is the
closest condensation to the HH 80N/81/80N outflow, in case of having
outflow-core dynamical interaction, it should be perturbed first and be the
most evolved condensation in the core. Therefore, the derived evolutionary
sequence for SE and IRS1 makes the outflow triggered star formation on IRS1
unlikely.
