N-rich stars orbital classification

We use the newly measured proper motions from Gaia Data Release 2 with existing line-of-sight velocities from the second generation of the Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) and spectrophotometric distance estimations from STARHORSE.

We adopted a set of high-resolution particle simulations evolved in the same steady-state Galactic potential model with a bar, in order to identify the groups of N-rich stars that have a high probability of belonging to the bulge/bar, disc and stellar halo component. We find that the vast majority of the N-rich stars show typically maximum height from the Galactic plane below 3kpc, and develop eccentric orbits (e>0.5), which means that these stars appear to have bulge/bar-like and/or halo-like orbits.