Phosphorus Abundances in the Hyades and Galactic Disk

• Published in: The Astronomical journal 2019-12, Vol.158 (6), p.219
• Main Authors: Maas, Z. G., Cescutti, G., Pilachowski, C. A.
• Format: Article
• Language: English
• Subjects: Abundance; Astronomy; Chemical evolution; Dwarf stars; Evolution; Galactic disk; Infrared spectra; Iron; Luminosity; Milky Way disk; Open star clusters; Organic chemistry; Phosphorus; Silicon; Stellar abundances; Stellar evolution; Temperature dependence; Temperature effects; Titanium
• ISSN: 0004-6256; 1538-3881
• DOI: 10.3847/1538-3881/ab4a1a

We have measured phosphorus abundances in nine disk stars between −1 < [Fe/H] < -0.5 and in 12 members of the Hyades open cluster using two P I lines at 1.06 m. High-resolution infrared spectra were obtained using Phoenix on Gemini South and abundances were determined by comparing synthetic spectra to the observations. The average abundance for the dwarf stars in our Hyades sample was = -0.01 0.06 and dex for the three giants. The consistency suggests that abundances derived using the 1.06 m P I lines are not subjected to temperature- or luminosity-dependent systematic effects at high metallicities. Our [P/Fe] ratios measured in disk stars are consistent with chemical evolution models with P yields increased by a factor of 2.75. We find that [P/O], [P/Mg], [P/Si], and [P/Ti] ratios are consistent with the solar ratio over a range of −1.0 < [Fe/H] < 0.2 with the [P/Si] ratio increasing by ∼0.1-0.2 dex at the lowest [Fe/H] ratios. Finally, the evolution of [P/Fe] with age is similar to other elements, providing evidence that P is produced at the same sites.