OBSERVATIONS OF SIO (V = 0, 1, 2) J = 3-2 AND J = 2-1 EMISSION IN LATE-TYPE STARS

Observations of SiO v = 0, 1, 2, J = 3-2 transitions were carried out for 42 late-type stars containing SiO v = 1, J = 2-1 maser emission wi th the 14 m radio telescope at Taeduk Radio Astronomy Observatory (TRA O) during 1995 February and 1996 February. Observations of the v = 0, 1, 2, J = 2-1 transitions in the same objects were performed within 40 days of the former observations using the same telescope. For SiO v = 1, J = 3-2 masers, the line was detected in 23 stars giving a detecti on rate of 55%. Seventeen of them were new detections. For SiO v = 2, J = 3-2 masers, the line was detected in seven stars, four of them bei ng new detections. The v = 2, J = 3-2 line intensities were found at t he expected intensity, unlike the anomalously weak emission seen previ ously in the rare v = 2, J = 2-1 maser. We also report the intensity r atios observed within the vibrational and rotational states.