# Chemodynamics of newly identified giants with globular cluster like abundance patterns in the bulge, disk, and halo of the Milky Way

## TL;DR

This study identifies and characterizes 31 nitrogen-rich giant stars in the Milky Way, revealing their unique chemical patterns and possible origins from globular clusters or disrupted dwarf galaxies, using APOGEE survey data.

## Contribution

It uncovers a new population of nitrogen-rich giants with distinct chemical and orbital properties, linking them to globular clusters and the Galaxy's accretion history.

## Key findings

- 31 nitrogen-rich giants identified with high [N/Fe]
- Some stars share orbital properties with the bulge/bar
- Chemistry suggests origins from globular clusters or dwarf galaxies

## Abstract

The latest edition of the APOGEE-2/DR14 survey catalogue and the first \texttt{Payne} data release of APOGEE abundance determinations by Ting et al. are examined. We identify 31 previously unremarked metal-poor giant stars with anomalously high levels of nitrogen in the chemical space defined by [Fe/H] and [N/Fe]. The APOGEE chemical abundance patterns of such objects revealed that these are chemically distinct from the Milky Way (MW) in most chemical elements. We have found all these objects have a [N/Fe]$>+0.5$, and are thus identified here as nitrogen-rich stars. An orbital analysis of these objects revealed that a handful of them shares the orbital properties of the bar/bulge, and possibly linked to tidal debris of surviving globular clusters trapped into the bar component. 3 of the 31 stars are actually halo interlopers into the bulge area, which suggests that halo contamination is not insignificant when studying N-rich stars found in the inner Galaxy, whereas the rest of the N-rich stars share orbital properties with the halo population. Most of the newly identified population exhibit chemistry similar to the so-called \textit{second-generation} globular cluster stars (enriched in aluminum, [Al/Fe]$>+0.5$), whereas a handful of them exhibit lower abundances of aluminum, [Al/Fe]$<+0.5$, which are thought to be chemically associated with the \textit{first-generation} of stars, as seen in globular clusters, or compatible with origin from a tidally disrupted dwarf galaxy.