All Figures

Figure 1: According to a point-axial system close to axial symmetry, the graph shows how the excess of radial mean velocity , referring to a pure axial system, and the mean rotation velocity  are related. The plotted points correspond to several increasing thick disk populations selected for  km s-1. The continuous line is the regression curve of the points according to Eq. (15), which intersects the horizontal axis at   2 km s-1. This value corresponds to the mean rotational velocity of the extrapolated thick disk.

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In the text

Figure 2: The graph shows the location of the young disk population centroid A2 and partial disk populations up to the complete thick disk T, which share a common direction in the plane of radial-rotation heliocentric velocities UV. Their straight line fit is extrapolated up to the heliocentric rotation velocity V=-82  2 km s-1 (horizontal dashed line) of the asymptotic thick disk, with zero radial mean velocity. Hence the heliocentric radial velocity of such an axisymmetric population may be estimated as U=-20  1 km s-1 (vertical dashed line), which is very close to the mean radial velocity of the early-type population A1.

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In the text

	Figure 3: For increasing thick disk populations, the difference between both regression curves, a)  and b) U0, measures the non-vanishing time-dependent term of the radial mean velocity for a pure axial system. The graphic uses galactocentric UV velocities. The discontinuous line shows the estimation of the no net radial motion point obtained from a linear extrapolation as in previous work.
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In the text