Boson dark matter halos with a dominant noncondensed component
  We consider galaxy halos formed by dark matter bosons with mass in the range
of about a few tens or hundreds eV. A major part of the particles is in a
noncondensed state and described under the Thomas-Fermi approach. Derived
equations are solved numerically to find the halo density profile. The
noncondensed state is supported in the entire halo except compact
gravitationally bounded Bose-Einstein condensates. Although the size of these
compact objects, also known as Bose stars, depends on interactions between the
particles, its upper limit is only about 100 astronomical units. The Bose stars
collect the condensed bosons providing a density cusp avoidance in the halo as
well as a natural mechanism to prevent overproduction of small halos. Clusters
of the Bose stars can also contribute to the halo density profile. The model is
analyzed by confronting its predictions with observations of galaxy rotation
curves. We employ 22 low surface brightness galaxies and obtain that the model
is consistent with the observational data when the particle mass is in the
range above about 50 eV and the best fit corresponds to the mass $m=86$ eV.
This mass is appropriate for relic dark matter bosons, which decouple just
after QCD phase transition.
