Radio Detection of Interstellar Dimethyl Ether

Abstract

Interstellar dimethyl ether, (CH3)2O, has been detected in emission from the direction of the Orion Nebula molecular cloud. The observed velocity of the 6 H 515 transition at 90.9 GHz is in excellent agreement with other molecules observed toward Orion. Observations of the 2 H 2 transition at 86.2 GHz and the 2ii H 2 at 31.1 GHz support the dimethyl ether detection and indicate that either (CH3)2O has two distinct velocity components in Orion or certain internal motion states are preferentially populated. This molecule has a large collisional cross-section and Csv symmetry; hence it should be useful for future studies of molecular pumping models. Subject headings: molecules, interstellar - Orion Nebula