Magnetic vortices from a nonlinear sigma model with local symmetry

We consider a nonlinear O(3) model in 2 + 1 dimensions minimally coupled to Chern-Simons gauge fields. All the static, finite-energy regular solutions of the model are discussed. Through a suitable reduction of the gauge group, the given solutions are mapped into an Abelian purely magnetic vortex. A two-dimensional Euclidean action reproducing such a vortex is also obtained and is that of an Abelian-Higgs model with topological term.