The radial gradient of cosmic ray intensity in the Galaxy
  The dependence of the cosmic ray intensity on Galactocentric distance is
known to be much less rapid than that to be thought-to-be sources: supernova
remnants. This is an old problem ('the radial gradient problem') which has led
to a number of possible 'scenarios'. Here, we use recent data on the
supernova's radial distribution and correlate it with the measured HII electron
temperature ({\em T}). We examined two models of cosmic ray injection and
acceleration and in both of them the injection efficiency increases with
increasing ambient temperature {\em T}. The increase is expected to vary as a
high power of {\em T} in view of the strong temperature dependence of the tail
of the Maxwell-Boltzmann distribution of particle energies. Writing the
efficiency as proportional to $T^n$ we find $n\approx 8.4$. There is thus, yet
another possible explanation of the radial gradient problem.
