86 GHz SiO masing late-type stars in the Inner Galaxy

Maria Messineo1 et al.

1 Leiden Observatory, Netherlands

E-mail contact: messineo@strw.leidenuniv.nl

Messineo M., Habing H., Sjouwerman L., Omont A. & Menten K. accepted by A&A Journal (astro-ph/0207284)

Messineo M., van der Bliek N., Blommaert J., Blum R., Habing H., van Loon J., Menten K., Omont A. & Sjouwerman L. in preparation

We present IRAM 30-m observations of 86 GHz (J=2-1, v=1) SiO maser emission of late-type stars toward the inner Galaxy. The stars were selected from the ISOGAL and MSX catalogues on the basis of their mid-infrared fluxes and colors. Our 255 new measurements of line-of-sight velocities double the number of maser line-of-sight velocities known toward the inner Galaxy. Combining our measurements with those from other surveys, in particular OH maser surveys, will allow a kinematic analysis of the stellar orbits in the inner Galaxy. Analyzing the colours and luminosities of OH and SiO maser emitters also yields new clues on the conditions under which different masers may occur. The new obtained longitude-velocity diagram clearly reveals a stellar nuclear disk component. Preliminary results from near-infrared spectra of those high velocity nuclear disk SiO masing stars taken in July with the CTIO 4-m will also be presented.