Density maps of the N-body simulation stars (left column), APOGEE stars (middle column), and our mock catalogue stars (right column). Top panel: face-on maps (X-Y-plane), with |X| < 1.5kpc distance bounds and ±20° longitude bounds in white, as well as a green line to guide the eye, indicating the angle of the Galactic bar and the Sun at X = −8.12 kpc,Y = 0 kpc (white star symbol). Bottom panels: corresponding maps in the Galactic (ℓ,b) plane. The colours indicate relative densities for each of the three catalogues separately.