  Many observations indicate the occurrence of ionised gas in the distant halos
of galaxies (including our own). Since photoionisation by stars (mainly O
stars, young or evolved low-mass stars depending on the kind of galaxy) does
not seem to be exclusively responsible for the ionisation of the hydrogen
filaments that should otherwise cool fast and recombine quickly, the question
arises which extra energy source can produce the quasistationary ionisation. We
show that stationary localized magnetic reconnection in current filaments may
contribute to the ionisation of the extraplanar halo gas. In these filaments
magnetic energy is dissipated. Consequently, the ionised as well as the neutral
component are heated and re-ionised on a time scale significantly shorter than
the recombination time scale. The amount of energy required for efficient
re-ionisation can in principle easily be provided by the free magnetic energy.
We present quasi-static models that are characterized by plasma temperatures
and densities that agree well with the observed values for the diffuse ionised
gas component of the interstellar medium. Plasma-neutral gas fluid simulations
are made to show that the recombination induced dynamical reconnection process
indeed works in a self-regulatory way.
