The following document lists the file abstract/TTSUJI_PROP_003.abs
from catalogue VI/111.
A plain copy of the file
(without headers/trailers) may be downloaded.
The great success of the IRAS survey has been much enhanced by the
low resolution spectroscopic (LRS) survey, and this fact clearly
demonstrates how the spectroscopic information is important in
understanding the infrared photometric survey. However, IRAS LRS
survey is restricted to nearby carbon stars of the Galactic disk. A
motivation of the present proposal is to extend infrared spectro-
scopic survey to carbon stars beyond the Galactic disk.
Especially, it is well known that the evolution of AGB stars
depends critically on the metallicity, and it is essential to study
carbon stars in different stellar systems with different metallicity.
For this reason, we propose to extend infrared spectroscopic survey
to carbon stars in the two nearby metal poor systems: the Galactic
halo (CH stars) and the LMC.
Major scientific goals of our proposal are:
1) To clarify how infrared spectra depends on metallicity. For
example,are they consistent with the prediction of model atmospheres?
2) To clarify how the formation of dust in circumstellar envelopes
of carbon stars depends on metallicity. Or could dust be formed in
metal-poor carbon stars?
3) To clarify the relationship of the chemistry in the photosphere
and that in the circumstellar envelope for metallicities different
from those in disk carbon stars. Especially, do J type carbon stars
in the LMC show silicate emission as for some J stars in the Galactic
disk? In fact, why some carbon stars, actually a considerable
fraction of the J type stars, at least those in the Galactic disk,
pass a stage that show silicate emission remains unresolved.
4) To clarify the evolution of the spectroscopic characteristics
in carbon stars of the LMC for which the distance is known, and hence
the HR diagram of carbon stars can be defined clearly.
5) To clarify the evolution of AGB stars in the metal poor era.