GALACTIC MAGNETISM AND THE ROTATION CURVES OF M31 AND THE MILKY-WAY

Can a magnetic held in a spiral galaxy speed up the interstellar gas i n its circular galactic rotation, faster than the stars move around th e galaxy? If so, a recently proposed magnetic-support model for a fast er gas could explain the flat-type rotation curves of the interstellar gas moving around a galaxy's center, rendering dark matter unnecessar y. But how strong must this magnetic field be? I find that in M31 and the Milky Way, the predicted magnetic field strengths (for magnetic su pport of the gas) are a factor more than 2 times the observational val ues. The predicted magnetic energies are a factor more than 4 times th e observed magnetic energies. These observations contradict the magnet ic-support theory of the gas, in M31 and the Milky Way.