SCIENTIFIC ABSTRACT
We propose to carry out high spectral resolution observations of atomic and
molecular lines from the outflows around a number of cool evolved objects.
These observations will address the following questions: (a) Can direct
observational evidence be provided for the first time showing the operation of
the proposed IR radiative pump mechanism for OH maser emission? (b) What is the
abundance of H2O in O-rich winds? It has been proposed that OH originates
mainly from H2O dissociation and, further, that H2O can be an important coolant
in such winds.


OBSERVATION SUMMARY
We will use the SWS Fabry-Perot to observe the 34.6um doublet, which should be
in absorption, as it is believed to pump the observed OH maser lines in the
microwave region. The LWS Fabry-Perots will be used to observe seven OH
doublets at 48.76um, 53.31um, 79.15um, 96.34um, 98.73um, 119.34um and 163.26um
which  are predicted to be part of the resulting emission cascade which leads
to the inversion of the OH ground state. The SWS and LWS observations will be
tied as closely together in time as possible for each target, due to the known
strong variability of the OH masers. LWS FP observations will also be obtained
at the wavelengths of three H2O rotational lines, at 108.07um, 136.50um and
179.53um, whose fluxes are predicted to be  detectable from a number of
objects, in an effort to diagnose how important H2O is as a coolant in the
outflows.

If targets in the Orion-hole should be observable (i.e. a  Spring launch), the
total amount of LWS Guaranteed (spacecraft) time allocated will be 19.86 hours,
of which 7.51 hours will be for Priority 1 targets. For an Autumn launch
(Sagittarius-hole observable), 19.38 hours of LWS Guaranteed (spacecraft) time
will be allocated, of which 7.31 hours will be for Priority 1 targets.
3.5 hours of Mission Scientist (H.J. Habing) Guaranteed time is being
used for this project, with the remainder coming from LWS Consortium 
Guaranteed time.