Lower Redshift Analogues of the Sources of Reionization
  Known populations of QSOs appear to fall short of producing the ionizing flux
required for re-ionizing the universe. The alternative, galaxies as sources of
ionizing photons, suffers from the problem that known types of galaxies are
almost completely opaque to ionizing photons. For reionization to happen,
either large numbers of (largely undiscovered) sources are required, or the
known populations of galaxies need to have had a much larger escape fraction
for ionizing radiation in the past. We discuss recent discoveries of faint z~3
Lyman alpha emitters with asymmetric, extended Lyman alpha emission regions,
which apparently are related to interacting galaxies. The unusually shaped line
profiles and the underlying stellar populations of these objects suggest the
presence of damaged gaseous halos, infall of gas, tidal or stripped stellar
features and young populations of hot stars, that would all be conducive to the
release of ionizing radiation. As galaxy interactions and mergers increase with
redshift, these effects can only become more important at earlier times, and so
these interacting z~3 objects may be late, lower redshift analogues of the
sources of reionization.
