This project will explore the evolution of galaxies during the intermediate epoch of the history of the universe, an important time when star formation is near its peak level and significant evolution in the ionizing radiation field is happening. The probe of this era is quasar absorption lines, which provide detailed information about kinematics, chemical content, and ionization conditions of the multiple phases of gas in and around galaxies. Much of the data and all of the tools are already in hand, so that analysis will begin immediately. Themes of this study include the evolution of galaxy coronae, of the high velocity cloud population, of the interstellar medium of galaxies, and of absorption produced by superwinds. Over half of the systems to be studied are small single-cloud, weak absorbers, a rather mysterious but abundant population.
The research will continue to involve students, including as authors on resultant publications (a significant prior strength of this team). This project also supports continued ambitious astronomy outreach at Pennsylvania State University. Reaching over 10,000 K-12 students, adults and educators each year, these activities culminate in the Astrofest, a four-night summer festival of astronomy conceived by undergraduates and sustained by more than 50 faculty and student volunteers.
