We propose SWS full scan observations of 10 evolved stars and two objects
with unusual spectra which have been observed by two spectrometers on board
the IRTS, a Japanese infrared satellite operated in the spring of 1995.
The main goal of this program is to obtain high quality spectra of some
representative objects in the IRTS data, and to apply the knowledge gained
from the high resolution ISO data to the thousands of IRTS spectra,
which will enable us to investigate the infrared properties of all the IRTS
objects from a statistical point of view. The spectrometers on the IRTS
covered a wavelength range from 1.4 to 12 microns. Much of this range cannot
be observed from ground based facilities. The IRTS mission surveyed 7% of
the sky and detected more than ten thousands point sources. However,
the spectral resolution of IRTS data are not high enough for the detailed
studies of these infrared sources. High-resolution spectra taken by ISO/SWS
can help our quantitative interpretation of the IRTS spectra.
Two unusual objects have been found. Both of them show sharp and strong
emission feature at 9 micron, which have never been identified with any
molecular or dust features. We propose to search another features associate
to these objects in the SWS spectra up to 45 micron. Such data will be a key
information to study the origin of this 9 micron feature.
ISO/SWS is presently the only instrument available with the same wavelength
coverage as the IRTS spectrometers. The IRTS and the ISO/SWS capabilities are
complementary and combining the results from each will maximize the scientific
results.