Rotation Dynamics of a Galaxy with a Double Mass Distribution
  The rotation dynamics of spiral galaxies is modeled using a sum of two mass distributions: a spherical bulge and a thin disk. The density functions representing these mass distributions are calculated from the total angular momentum of the galaxy and known rotation curves. When both bulge and disk density functions are assumed to be smooth and are given a value of zero beyond the edge of the galaxy, a unique solution is obtained. Moreover, the calculated density functions show that constant rotation curves are obtained from a nearly exponential luminosity profile with a dark matter distribution which follows that of the light emitting matter, without the need for modified Newtonian dynamics. Experimental detection of molecular hydrogen in spiral galaxies confirms the presence of a baryonic massive component consistent with the results obtained with this model. It is proposed that dark matter does not have to be exotic non-baryonic matter. Instead, it can be made of molecular hydrogen and condensed matter. 
Louis Marmet
astro-ph.GA physics.comp-ph