Dynamics of Distant Normal Galaxies

Masses of galaxies are beginning to be measured systematically at redshifts z > 0.3. Such data provide powerful and unique links and clues to theories, simulations, and our understanding of early galaxy formation and evolution. Discriminating masses of different kinds (e.g., dark matter, old stars, HI gas) remains difficult, but a wide variety of techniques for measuring total dynamical masses are being explored and found practical. I highlight three recent optical studies of dynamical masses: 1) the emission line velocity widths of blue galaxies and rotation curves of spirals that trace evolution in the Tully-Fisher relation to z ~ 1; 2) the absorption line velocity dispersions of early type galaxies in the field and clusters to track evolution in the Fundamental Plane to z ~ 0.85; and 3) the kinematics of high redshift (z ~ 3) Lyman-drop galaxies to constrain their nature, descendents, and progenitors. The next decade shows promise of an explosive growth in this infant field of measuring masses, especially in having much larger sample sizes, higher precision and S/N, improved techniques and tools, and probes of more diverse kinds of mass.