J. Sanchez Almeida (1, 2), M. E. Filho (1, 2,, 3), C. Dalla Vecchia (1, 2), E. D. Skillman (4) ((1) Instituto de Astrofisica de Canarias, La Laguna, Tenerife, Spain, (2) Departamento de Astrofisica, Universidad de La Laguna, (3) SIM/FEUP, Porto, Portugal, (4) Minnesota Institute for Astrophysics, School of Physics, Astronomy, University of Minnesota, Minneapolis, USA.)
