Tracing the Galactic Past: Chemical Clues from the Milky Way’s Faint Companions
Cheng Xu and collaborators used APOGEE data to study the chemical makeup of four dwarf galaxies orbiting the Milky Way. They found that galaxy mass influences how elements like magnesium and iron evolve over time, with larger galaxies retaining alpha elements longer. In Fornax, they discovered nitrogen-rich stars likely from disrupted globular clusters, offering clues about early star formation and galactic evolution.
Ghosts and Companions of the Milky Way: What Dwarf Galaxies Tell Us About Galaxy Formation
Grimozzi et al. used simulations to compare gas in disrupted and surviving dwarf galaxies around the Milky Way. They found that disrupted dwarfs, accreted earlier, have lower metallicity and higher [Mg/Fe], reflecting bursty star formation. These chemical differences reveal how timing influences galaxy evolution in the Milky Way’s past.