SiO Emission from a 1000 AU Disk in Orion KL

Abstract

We mapped the v = 1 and v = 0, J = 2--1 transitions of SiO in Orion KL with 0."5 angular resolution. The v = 1 emission originates from an 80 AU diameter ring of maser spots centered on radio continuum source I, while the v = 0 emission appears to delineate a ~1000 AU diameter flared disk centered on source I, with long axis perpendicular to the Orion KL bipolar outflow. The v = 0 line has brightness temperatures as high as 3000 K, probably indicating regions of weak maser emission.