Simulation of the X-shaped bulge of the Milky Way

Animation of a barred galaxy like the Milky Way showing the presence of an X-shaped bulge.  The X-shape extends to about one half of the bar radius.  It is directly visible when the bar is seen from the side, but when the viewer is close to the long axis of the bar it cannot be seen directly and its presence can only be inferred from the distribution of brightnesses of stars along a given direction.