We consider the effect of the differential rotation of the disk of the Galaxy on magnetic field which penetrates the disk. The magnetic field will be progressively distorted from a potential current-free form and will at some stage become unstable. We expect, from knowledge of solar flares, that an MHD instability, a resistive instability, or a combination of the two, will result in the release of the excess magnetic energy and that part of the released energy will be converted into heat. By estimating the energy release and the rate at which this process will occur and by assuming that this energy input is balanced by radiation, we obtain estimates of the parameters of the resulting plasma. It appears that this process alone can heat a galactic corona to temperatures of order 1,000,000 K. Author
Sponsored in part by Grant Nos. NGL-05-020-272 and NGR-05-020-668.