| Description |
The chemical composition of a galaxy changes as it evolves, so understanding the evolutionary processes of individual elements can be powerful tools in unravelling the history of a galaxy. Phosphorus is considered one of the key building blocks of life, and sulfur is an alpha-element, a tracer of supernovae in a galaxy's past. The nucleosynthetic origins and chemical evolution of both phosphorus and sulfur are still debated, due to the lack of absorption lines in optical wavelengths. The Sloan Digital Sky Survey's APO Galactic Evolution Experiment (APOGEE) is a high-resolution infrared spectroscopic survey which can uniquely derive abundances for these elements in over 100,000 stars in the Milky Way galaxy. Specifically, probing stellar sub-populations such as star clusters can reveal chemical evolutionary trends. We present analysis from 854 stars in 124 open clusters covered in the APOGEE survey. We find that phosphorus behaves like an a-element, indicating that both phosphorus and sulfur are primarily synthesized in Type II supernovae. We find no significant galactic gradient trends for sulfur, and a slight gradient of 0.01 dex kpc_1 for phosphorus. |
