HI shells in the Leiden/Argentina/Bonn HI survey
  We analyse the all-sky Leiden/Argentina/Bonn HI survey, where we identify
shells belonging to the Milky Way. We used an identification method based on
the search of continuous regions of a low brightness temperature that are
compatible with given properties of HI shells. We found 333 shells in the whole
Galaxy. The size distribution of shells in the outer Galaxy is fitted by a
power law with the coefficient of 2.6 corresponding to the index 1.8 in the
distribution of energy sources. Their surface density decreases exponentially
with a scale length of 2.8 kpc. The surface density of shells with radii >= 100
pc in the solar neighbourhood is around 4 per kpc^2 and the 2D porosity is
approximately 0.7.
