Dynamical Orbital classification of selected N-rich stars with
  \textit{Gaia} DR2 astrometry
  We have used the galaxy modeling algorithm \texttt{GravPot16}, to explore the
more probable orbital elements of a sample of 64 selected N-rich stars across
the Milky Way. Using the newly measured proper motions from \texttt{Gaia} DR2
with existing line-of-sight velocities from APOGEE-2 survey and
spectrophotometric distance estimations from the \texttt{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, disk, and
stellar halo component. We find that the vast majority of the N-rich stars show
typically maximum height from the Galactic plane below 3 kpc, and develop
rather eccentric orbits (\textit{e}$>$0.5), which means these stars appear to
have bulge/bar-like and/or halo-like orbits. We also show that $\sim66$\% of
the selected N-rich stars currently lives in the inner Galaxy inside the
corotation radius (C.R.), whilst $\sim14$\% of the N-rich star resides in
halo-like orbits. Among the N-rich in the inner Galaxy, $\sim27\%$ of them
share orbital properties in the boundary between bulge/bar and disk, depending
on the bar pattern speeds. Our dynamical analysis also indicates that some of
the N-rich are likely halo interlopers and therefore suggest that halo
contamination is not insignificant within the bulge area.
