Oral Presentation
The M giants classification in the LAMOST DR1
We perform a discrimination method by using the spectral index diagram of TiO5 and CaH2+CaH3 to separate M giants
and Mdwarfs. Using the M giant spectra identified from the LAMOST DR1, we have successfully assembled a set of M giant templates with high signal-to-noise ratio. Combining with the M dwarf/subdwarf templates in Zhong et al. (2014), we present an extend M-type templates library which includes not only M dwarfs with well-defined temperature and metallicity grid but also M giants with temperature from M0 to M6. Then, the template-fit method were used to automatically identify and classify M-type stars from the LAMOST DR1. The result of M-type stars catalog is cross-matched with 2MASS JHKs infrared photometry. In addition,
we calculated the heliocentric radial velocity of all M type stars by using the cross-correlation method with the template spectrum in a zero-velocity rest frame. Using the relationship between the absolute infrared magnitude MJ and the spectroscopic subtype we classified, we derived the spectroscopic distance of M giants and dwarfs, with uncertainties about 40%. A completed catalog of 10044 M giants and 136251 M dwarfs/subdwarfs is provided.
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