SiO maser survey of AGB stars in the North Galactic Cap

A SiO maser survey in the J = 1-0, v = 1 and 2 transitions has been made fo r IRAS sources in the North Galactic Cap (b > 30 degrees) with the Nobeyama 45 m radio telescope. The sources were selected on the basis of their IRAS 12/25-mum and 25/60-mum flux ratios as likely oxygen-rich AGB candidates. SiO masers were detected from 24 out of the 97 selected sources, where 17 w ere new detections. The distances and heights above the Galactic plane are calculated. The Galactic distribution of detected and undetected stars indi cates that metallicity is likely to govern the detection rate. The Galactoc entric angular velocities of the subsampled stars are derived and their var iation with the Galactic height is discussed.