AST 9530590 Interstellar Matter and Magnetic Fields. In interstellar space the magnetic energy density is usually comparable to the turbulent energy density so that the field plays a very strong role in all physical processes. However, measurements of the magnetic field strength are very difficult because they are subject to contamination by instrumental effects, and the required sensitivity is high. Accordingly our knowledge of magnetic fields is limited by the observational data base. With this award Dr. Heiles will vigorously expand the data base on interstellar magnetic fields with observations of Zeeman splitting of atomic hydrogen, the hydroxyl radical, and radio recombination lines. He will also pursue morphological and kinematic studies of the diffuse interstellar medium in our Galaxy. ===============================================
