Rotation Curve and Mass Models of the Galaxy		Ay 124
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A typical operational procedure:

  -  Assume a mass distribution for the Galaxy
  -  Predict the rotation curve
  -  Compare with the observed r.c.

==> Rotation curve is essential!
    (Especially at large radii)

Refinements:

  - Match the star counts, star kinematics
  - Match the local disk kinematics (A, B)

Problems:

  - Non-circular motions, due to density asymmetries:
    local (e.g., spiral arms), and global (e.g.,
    warps, bars, interacting companions...)

  - Zero-point of the LSR

  - Selection effects and distance determinations
    for the outer disk tracers.

References:

  - GKK chapters 6, 10.  MB chap. 8.

  - Schmidt, M. 1965, in "Galactic Structure" (SSS V), eds. 
    A. Blaauw and M. Schmidt, p. 513.  Chicago: U. Ch. Press.

  - Caldwell, J., and Ostriker, J. 1981, Ap.J. 251, 61.

  - Bahcall, J., Schmidt, M., and Soneira, R. 1982, Ap.J. 258, L23.

  - Bahcall, J., Schmidt, M., and Soneira, R. 1983, Ap.J. 265, 730.

  - Knapp, G.R. 1983, in "Kinematics, Dynamics, and Structure of 
    the Milky Way", ed. W. Shuter, p. 233.  Dordrecht: D. Reidel.

  - Schmidt, M. 1985, in "The Milky Way Galaxy" (IAU 106),  eds. 
    van Woerden et al., p. 75.  Dordrecht: D. Reidel.

  - Fich, M., Blitz, L., and Stark, A. 1989, Ap.J. 342, 272.