The Abundance of Fluorine in Normal G and K Stars of the Galactic Thin Disk

TL;DR

This study measures fluorine abundances in G and K stars of the Galactic thin disk using infrared spectroscopy, revealing insights into the sources of fluorine, including supernovae and AGB stars, and their roles in Galactic chemical evolution.

Contribution

It provides the first detailed fluorine abundance measurements in thin disk stars, highlighting the significance of supernovae and AGB stars in fluorine production.

Findings

Average fluorine abundance [F/Fe] = +0.23 in thin disk stars

Fluorine abundance shows little variation with metallicity

Neutrino spallation in Type II supernovae likely major fluorine source

Abstract

The abundance of fluorine is determined from the (2-0) R9 2.3358 micron feature of the molecule HF for several dozen normal G and K stars in the Galactic thin disk from spectra obtained with the Phoenix IR spectrometer on the 2.1-m telescope at Kitt Peak. The abundances are analyzed in the context of Galactic chemical evolution to explore the contributions of supernovae and asymptotic giant branch (AGB) stars to the abundance of fluorine in the thin disk. The average abundance of fluorine in the thin disk is found to be [F/Fe] = +0.23 +/- 0.03, and the [F/Fe] ratio is flat or declines slowly with metallicity in the range from -0.6 < [Fe/H] < +0.3, within the limits of our estimated uncertainty. The measured abundance of fluorine and lack of variation with metallicity in Galactic thin disk stars suggest neutrino spallation in Type II supernovae contributes significantly to the Galactic fluorine abundance, although contributions from AGB stars may also be important.