Constraints on the distribution of supernova remnants with
  Galactocentric radius
  Supernova remnants (SNRs) in the Galaxy are an important source of energy
injection into the interstellar medium, and also of cosmic rays. Currently
there are 294 known SNRs in the Galaxy, and their distribution with
Galactocentric radius is of interest for various studies. Here I discuss some
of the statistics of Galactic SNRs, including the observational selection
effects that apply, and difficulties in obtaining distances for individual
remnants from the `Sigma-D' relation. Comparison of the observed Galactic
longitude distribution of a sample of bright Galactic SNRs -- which are not
strongly affected by selection effects -- with those expected from models is
used to constrain the Galactic distribution of SNRs. The best-fitting
power-law/exponential model is more concentrated towards the Galactic centre
than the widely used distribution obtained by Case & Bhattacharya (1998).
