Azimuthal and vertical actions of the stars from the SEGUE dataset (left), and corresponding energy-vertical angular momentum diagram (right). The green lines mark the locus of circular orbits in the Milky Way model. The red ellipse on the left panel shows clearly visible structure corresponding to the Sagittarius stream. The stars inside that selection are highlighted in red in the right panel. The stars between the red and blue ellipses in the left panel are used to estimate the background contamination, which is used in Fig. 6.