Fluorine in the Solar neighborhood: No evidence for the neutrino process
  Asymptotic Giant Branch stars are known to produce `cosmic' fluorine but it
is uncertain whether these stars are the main producers of fluorine in the
Solar neighborhood or if any of the other proposed formation sites, type II
supernovae and/or Wolf-Rayet stars, are more important. Recent articles have
proposed both Asymptotic Giant Branch stars as well as type II supernovae as
the dominant sources of fluorine in the Solar neighborhood.
  In this paper we set out to determine the fluorine abundance in a sample of
49 nearby, bright K-giants for which we previously have determined the stellar
parameters as well as alpha abundances homogeneously from optical
high-resolution spectra. The fluorine abundance is determined from a 2.3 $\mu$m
HF molecular line observed with the spectrometer Phoenix.
  We compare the fluorine abundances with those of alpha elements mainly
produced in type II supernovae and find that fluorine and the alpha-elements do
not evolve in lock-step, ruling out type II supernovae as the dominating
producers of fluorine in the Solar neighborhood.
  Furthermore, we find a secondary behavior of fluorine with respect to oxygen,
which is another evidence against the type II supernovae playing a large role
in the production of fluorine in the Solar neighborhood. This secondary
behavior of fluorine will put new constraints on stellar models of the other
two suggested production sites: Asymptotic Giant Branch stars and Wolf-Rayet
stars.
