Our Galaxy, the Milky Way, is a benchmark for understanding disk galaxies. It is the only galaxy whose formation history can be studied using the full distribution of stars from faint dwarfs to supergiants. The oldest components provide us with unique insight into how galaxies form and evolve over billions of years. The Galaxy is a luminous (L ) barred spiral with a central box/peanut bulge, a dominant disk, and a diffuse stellar halo. Based on global properties, it falls in the sparsely populated "green valley" region of the galaxy colour-magnitude diagram. Here we review the key integrated, structural and kinematic parameters of the Galaxy, and point to uncertainties as well as directions for future progress. Galactic studies will continue to play a fundamental role far into the future because there are measurements that can only be made in the near field and much of contemporary astrophysics depends on such observations.

Based on a uniform dynamical analysis of the line-profile shapes of 21 mostly luminous, slowly rotating, and nearly round elliptical galaxies, we have investigated the dynamical family relations and dark halo properties of ellipticals. Our results include: (i) The circular velocity curves (CVCs) of elliptical galaxies are flat to within ≃ 10% for R ∼ > 0.2R e . (ii) Most ellipticals are moderately radially anisotropic; their dynamical structure is surprisingly uniform. (iii) Elliptical galaxies follow a Tully-Fisher (TF) relation with marginally shallower slope than spiral galaxies, and v max c ≃ 300 km s −1 for an L * B galaxy. At given circular velocity, they are ∼ 1 mag fainter in B and ∼ 0.6 mag in R, and appear to have slightly lower baryonic mass than spirals, even for the maximum M/L B allowed by the kinematics. (iv) The luminosity dependence of M/L B indicated by the tilt of the Fundamental Plane (FP) is confirmed. The tilt of the FP is not caused by dynamical or photometric non-homology, although the latter might influence the slope of M/L versus L. It can also not be due only to an increasing dark matter fraction with L for the range of IMF currently discussed. It is, however, consistent with stellar population models based on published metallicities and ages. The main driver is therefore probably metallicity, and a secondary population effect is needed to explain the K-band tilt. (v) These results make it likely that elliptical galaxies have nearly maximal M/L B (minimal halos). (vi) Despite the uniformly flat CVCs, there is a spread in the luminous to dark matter ratio and in cumulative M/L B (r). Some galaxies have no indication for dark matter within 2R e , whereas for others we obtain local M/L B s of 20-30 at 2R e . (vii) In models with maximum stellar mass, the dark matter contributes ∼ 10 − 40% of the mass within R e . Equal interior mass of dark and luminous matter is predicted at ∼ 2−4R e . (viii) Even in these maximum stellar mass models, the halo core densities and phase-space densities are at least ∼ 25 times larger and the halo core radii ∼ 4 times smaller than in spiral galaxies of the same circular velocity. The increase in M/L sets in at ∼ 10 times larger acceleration than in spirals. This could imply that elliptical galaxy halos collapsed at high redshift or that some of the dark matter in ellipticals might be baryonic.The dynamical structure of these galaxies turned out to be remarkably uniform. Most galaxies require moderate radial anisotropy in their main bodies (at ∼ 0.5R e ). Their circular velocity curves are all consistent with being flat outside ≃ 0.2R e . The M/L ratio profiles begin to rise at around 0.5 − 2R e and are consistent with X-ray and other data where available, although from the kinematic data alone constant M/L models can only be ruled out at 95% confidence in a few galaxies.This sample provides a new and much improved basis for investigating the dynamical family properties of elliptical galaxies, which is the subject of the present study. In Section 2, we analyze...

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