Chemical Cartography with APOGEE: Mapping Disk Populations with a Two-Process Model and Residual Abundances

Understand

We apply a novel statistical analysis to measurements of 16 elemental abundances in 34,410 Milky Way disk stars from the final data release (DR17) of APOGEE-2.

• Building on recent work, we fit median abundance ratio trends [X/Mg] vs.
• [Mg/H] with a 2-process model, which decomposes abundance patterns into a "prompt" component tracing core collapse supernovae and a "delayed" component tracing Type Ia supernovae.
• For each sample star, we fit the amplitudes of these two components, then compute the residuals \Delta[X/H] from this two-parameter fit.