# Phosphorus Abundances in FGK Stars

## TL;DR

This study measures phosphorus abundances in FGK stars using high-resolution infrared spectra, confirming that current chemical evolution models underestimate phosphorus yields, and suggests increasing yields by a factor of 2.75 for better accuracy.

## Contribution

It provides new phosphorus abundance measurements in FGK stars and demonstrates that models need to increase phosphorus yields by 2.75 times to match observations.

## Key findings

- Phosphorus abundances are consistent with previous IR studies.
- Models underestimate phosphorus yields; increased by a factor of 2.75 improves fit.
- No significant deviations in P/Si and P/S ratios from solar values.

## Abstract

We measured phosphorus abundances in 22 FGK dwarfs and giants that span --0.55 $<$ [Fe/H] $<$ 0.2 using spectra obtained with the Phoenix high resolution infrared spectrometer on the Kitt Peak National Observatory Mayall 4m telescope, the Gemini South Telescope, and the Arcturus spectral atlas. We fit synthetic spectra to the P I feature at 10581 $\AA$ to determine abundances for our sample. Our results are consistent with previously measured phosphorus abundances; the average [P/Fe] ratio measured in [Fe/H] bins of 0.2 dex for our stars are within $\sim$ 1 $\sigma$ compared to averages from other IR phosphorus studies. Our study provides more evidence that models of chemical evolution using the results of theoretical yields are under producing phosphorus compared to the observed abundances. Our data better fit a chemical evolution model with phosphorus yields increased by a factor of 2.75 compared to models with unadjusted yields. We also found average [P/Si] = 0.02 $\pm$ 0.07 and [P/S] = 0.15 $\pm$ 0.15 for our sample, showing no significant deviations from the solar ratios for [P/Si] and [P/S] ratios.