Exploring the Heart of the Milky Way: A Study of Its Bulge Structure, Kinematics, and Stars
This study explores the Milky Way’s bulge using OGLE, APOGEE, and Gaia data, focusing on its structure, stellar populations, and dynamics. Researchers identified distinct central and inner bulge star groups, with the inner aligning with the Galactic bar and the central showing slower rotation. Chemical analyses revealed differences in star formation histories. A boxy bulge shape was supported over an X-shaped structure, highlighting the bulge's complex evolution from the Galactic disk.
Tracing the Origins of the Milky Way's Bulge
Tristan Boin et al. investigate puzzling velocity trends in the Milky Way’s bulge, where metal-rich stars exhibit high velocity dispersion near the midplane, reversing at higher latitudes. Using APOGEE data and N-body simulations, they show that the bulge's bar-like structure traps metal-rich, thin-disk stars more efficiently. This study reinforces the idea that the bulge forms from disk material rather than a classical spheroid.