The Chemical Evolution of Fluorine in the Bulge - High-resolution K-band
  spectra of giants in three fields
  Possible main formation sites of F in the Universe include AGB stars, the
{\nu}-process in Type II SNe, and/or W-R stars. The importance of the W-R stars
has theoretically been questioned and they are probably not needed in the
modelling of the chemical evolution of F in the solar neighborhood. It has,
however, been suggested that W-R stars are indeed needed to explain the
chemical evolution of F in the Bulge. The molecular spectral data of the often
used HF-molecule has not been presented in a complete and consistent way and
has recently been debated in the literature. In this article we determine the
[F/O] vs. [O/H] trend in the Bulge to investigate the possible contribution
from W-R stars. Additionally, we present here a HF line list for the K- and
L-bands (including the often used 23358.33 {\AA} line) and an accompanying
partition function. The F abundances were determined using spectral fitting
from hi-res NIR spectra of eight K giants recorded by the spectrograph CRIRES.
We have also re-analyzed five previously published Bulge giants using our new
HF molecular data. We find that the F-O abundance in the Bulge probably cannot
be explained with chemical evolution models including only AGB-stars and the
{\nu}-process in SNe Type II, i.e. a significant amount of F production in W-R
stars is likely needed to explain the F abundance in the Bulge. Concerning the
HF line list, we find that a possible reason for the inconsistencies in the
literature, with two different excitation energies being used, is two different
definitions of the zero-point energy for the HF molecule and therefore also two
accompanying different dissociation energies. Both line lists are correct, as
long as the corresponding consistent partition function is used in the spectral
synthesis. However, we suspect this has not been the case in several earlier
works leading to F abundances 0.3 dex too high.
