9457456 Goodman Dr. Goodman will carry out research to seek to explore the question of which physical processes are most important in determining the structure and evolution of interstellar clouds in our Galaxy. These "clouds", as they are known, are just local density enhancements in the lower-density interstellar medium (ISM), but they are nonetheless the object of intense study, primarily because they are the birthplaces of new stars in our Galaxy. Without a clear physical picture of these clouds, it is very difficult, if not impossible, to develop and refine a physically realistic scenario for the star formation process itself. Dr. Goodman, in carrying out the research, will specifically seek to explore the relationship between magnetic fields, density structure, and velocity structure in the interstellar medium (ISM). Prior research carried out by Dr. Goodman and collaborators has shown that the magnetic and kinetic energies measured in the gaseous ISM are usually similar, so it is reasonable to hypothesize that the magnetic fields pervading the gas and velocity structure in the gas are related. One of the biggest pieces missing from the picture of the interaction between magnetic fields and gas in the ISM is a clear view of magnetic field structure in the dense gas where stars form. The observation of the polarization of optical and near-infrared background starlight can be used to map field structure in low-density gas, but Dr. Goodman's recent research has shown that this technique cannot trace the field accurately in denser gas. Dr. Goodman and collaborators will therefore carry out far-infrared and sub-millimeter wavelength observations of the polarized emission from magnetically aligned dust in dense regions of the ISM. The results of the research should provide a clearer view of the field structure there. The observations will be carried out through several international collaborations, one of which will seek to use the new infrared satellite observatory (ISO). Velocity structure of the ISM will be investigated with new spectral-line mapping of gas in the interstellar medium and through theoretical modeling of new and existing data. Dr. Goodman's current students and research assistants will be primarily working on this line of inquiry. Early results of the research have shown that "dense cores", which are the dense knots of gas associated with the formation of individual stars, may represent "eddies" in a more turbulent/wavelike velocity field which characterizes the lower-density surrounding ISM. The new studies will focus on relating the velocity structure deduced from spectral-line mapping to realistic views of the magnetic field in the ISM obtained from far-infrared and sub-mm polarimetry. This award is to recognize an outstanding young faculty member in science and engineering. The award will enhance the career of the faculty member by providing flexible support for research and educational activities. Cooperation with industry and institutions that support research and education is encouraged.
