Contents of: VI/111/./abstract/TTSUJI_PROP_003.abs

The following document lists the file abstract/TTSUJI_PROP_003.abs from catalogue VI/111.
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   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.

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