W. H. Vanderbilt Professor, Astronomy Department, University of Virginia, 2025-

Professor, Astronomy Department, University of Virginia, 2009-

Associate Professor, Astronomy Department, University of Virginia, 2003-2009

Assistant Professor, Astronomy Department, University of Virginia, 1997-2003

Fairchild Prize Fellow, Theoretical Astrophysics, CalTech, 1996-1997 (Advisors: Roger Blandford & Peter Goldreich)

Theoretical Astrophysics Center Postdoc, UC Berkeley, 1993-1996 (Advisors: Frank Shu & Chris McKee)

Research Assistant, JILA, University of Colorado, 1988-1993 (Advisor: Mitch Begelman)

Teaching Assistant, Physics Department, University of Colorado, 1987-1988