Compact objects (neutron stars and black holes) are known principally from the effects of mass transfer onto them, thus the understanding of mass transfer and its consequences are fundamental to our understanding of many aspects of the final stages of stellar evolution. Dr. Vrtilek will use a set of narrow spectral features in the X-ray, ultraviolet, and visible, selected because they provide important diagnostics of plasma conditions, to study mass transfer processes and accretion disk structure in X-ray binaries. Emphasis on multiwavelength spectral analysis is important as binary X-ray sources are strong emitters over a broad range of the electromagnetic spectrum with each part of the spectrum contributing distinct and often time-variable information. Recently developed theoretical models that predict the characteristics of line emission over the range from the Hell recombination line at 4686m to the iron K-shell emission between 6-7 keV will be tested against the observations. This work relies on a balanced mix of existing data, approved observations with currently operating spacecraft, and detailed plans for the use of future missions. Interactive activities at the host institution include teaching a graduate course in X-ray astronomy, a field not currently represented on the faculty of the host institution. Dr. Vrtilek will also organize a series of guest lectures, drawing upon experts who will discuss the programs and functions of other area institutions, supplemented by lectures on techniques of scientific presentation, proposal preparation, and other "survival skills" for graduate students. A workshop on careers in the physical sciences will be held for area high school students, particularly women and minorities. This project furthers VPW program objectives which are (1) to provide opportunities for women to advance their careers in engineering and in the disciplines of science supported by NSF and (2) to encourage women to pursue careers in science and engineering by providing greater visibility for women scientists and engineers employed in industry, government, and academic institutions. By encouraging the participation of women in science, it is a valuable investment in the Nation's future scientific vitality.
