The following document lists the file abstract/TTSUJI_PROP_004.abs
from catalogue VI/111.
A plain copy of the file
(without headers/trailers) may be downloaded.
We propose to extend spectrophotometry of M dwarf stars by PHOT-S
with photometric calibration by PHOT-P to very late M dwarfs near the
end of the main sequence. The purpose of our proposal is to clarify
the infrared properties of very low mass stars (VLMSs) and establish
the relationship of them to the basic physical properties of such
stars. So far, little is known on the infrared spectra of M dwarfs
(especially beyond 2.5 micron) because of their extreme faintness,
but this knowledge should be very important to understand the
atmospheric structure of M dwarfs and also as a basis of our future
studies of brown dwarfs. We hope to obtain the infrared spectral
energy distributions between 2.5 and 12 micron (except for a gap in
5-6 micron) by PHOT-S with photometric calibration by PHOT-P, and also
extend the photometry to IRAS bands. The major scientific goals by our
observations are:
1) To test the model atmospheres by comparing observed infrared
flux with the predictions based on a new grid of model atmospheres of
VLMSs covering the Teff range between 1,000 and 4,000K for the
metallicities of the disk and halo (see Sect.4), and to determine the
basic physical parameters of the atmospheres of M (sub)dwarfs.
2) To examine if there is any observational evidence such as
silicate band at around 10 micron to show the dust formation in the
dense and cool atmospheres of VLMSs.
3) To explore a possibility if an indication of the temperature
inversion due to coronal heating can be found in the infrared where
opacity is increasing due to the quasi-continuous absorption by the
collision induced dipole transitions of H2 molecule and if this can
resolve some known inconsistencies between observations and model
predictions.