SiO maser survey of southern IRAS sources

Abstract

We have surveyed 163 southern IRAS sources in the SiO J = 2 - 1 v = 1 maser line at 86 GHz, obtaining 38 (22 new and 16 previously known) detections. These detections include 6 stars not previously detected in OH 1612 MHz surveys, and 4 sources assigned incorrect OH radial velocities. The distance reachable in this survey turned out to be about 4 kpc. The local velocity dispersion near the Sun were found to be approximately 30 km s-1 for these IRAS/SiO sources. A relatively high concentration of the SiO detected sources were found at the area 320° < l < 340° (toward ``Norma tangent''). The estimated distances for these sources suggest that this concentration is spread between 2 and 6 kpc from the Sun, peaking on the Scutum-Crux arm.