86 GHz SiO maser survey of late-type stars in the inner Galaxy

Abstract

We present a compilation and study of DENIS, 2MASS, ISOGAL, MSX and IRAS 1–25 μm photometry for a sample of 441 late-type stars in the inner Galaxy, which we previously searched for 86 GHz SiO maser emission [CITE]. The comparison of the DENIS and 2MASS J and KS magnitudes shows that most of the SiO targets are indeed variable stars. The MSX colours and the IRAS colour of our SiO targets are consistent with those of Mira type stars with dust silicate feature at 9.7 μm feature in emission, indicating only a moderate mass-loss rate.