Laboratory Studies of Astronomically Relevant Dust Species

点击翻译按钮获取中文摘要

Dr. Hecht and his colleagues at the Aerospace Corporation will provide new laboratory data on small clusters of molecular species which are relevant to various models of interstellar material. The primary species to be studied are polycyclic aromatic hydrocarbon (PAH) monomers and clusters. Until the 1980s models for interstellar and circumstellar dust did not need to include individual grains smaller than 50 Angstroms. This changed due to a series of excellent observations in the infrared. These measurements revealed emission whose origin has only been explained to date by postulation of a significant amount of interstellar material with radii from 3 to 50 Angstroms. Laboratory instrumentation has also been developed where, for the first time, clusters of from 2 to 1000 atoms formed from a variety of materials can be produced as a molecular beam. Experiments using such an apparatus have shown that for some materials certain sized clusters are unusually stable. Dr. Hecht will use laboratory instrumentation that incorporates the latest in technological advances to produce and study small particles of potential astronomical importance.