My teaching and research interests in astrophysics include studies of galaxy formation, the ionizing continuum and broad emission lines of quasars, interstellar and intergalactic matter, supernova remnants, and the reionization epochs of hydrogen and helium in the high-redshift universe. My group carries out Hubble Space Telescope observations of the intergalactic medium, quasars, gamma-ray burst host galaxies, and high-redshift galaxies. I emphasize research on atomic, molecular, and radiative processes in astrophysics. Theoretical work involves analytic and computational analysis of physical conditions applied to the high-redshift universe. Space-observational research includes ultraviolet, optical, and infrared studies with the Hubble Space Telescope (Wide-Field Camera-3 and Cosmic Origins Spectrograph).