We present a chemodynamical study of the Triangulum-Andromeda overdensity (TriAnd) employing a sample of 31 candidate stars observed with the GRACES high-resolution (R=40,000) spectrograph at the Gemini North (8.1 m) telescope. TriAnd is a stellar substructure found toward the outer disk of the Milky Way, located at RGC∼18 kpc from the Sun, toward Galactic latitude b∼25{\deg}. Most stars in our sample have dynamical properties compatible with a disk stellar population. In addition, by applying an eccentricity cut, we are able to detect a stellar contamination that seems to be consistent with an accreted population. In chemical abundance space, the majority of our TriAnd candidates are similar to the outer thin-disk population, suggesting that the overdensity has an \textit{in situ} origin. Finally, the found accreted halo interlopers spatially overlapping with TriAnd should explain the historical discussion of the overdensity's nature due to its complex chemical patterns.
@article{arxiv.2304.00156,
title = {The Chemodynamical Nature of the Triangulum-Andromeda Overdensity},
author = {Yuri Abuchaim and Hélio D. Perottoni and Silvia Rossi and Guilherme Limberg and Angeles Pérez-Villegas and Rafael M. Santucci and Vinicius M. Placco and João V. Sales-Silva and Friedrich Anders and Helio J. Rocha-Pinto},
journal= {arXiv preprint arXiv:2304.00156},
year = {2023}
}