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 \ion P1 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 .