1. Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool L3 5RF, UK
2. Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325, USA
3. Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada
4. Instituto de Astrofisica de Canarias, Via Lactea, 38205 La Laguna, Tenerife, Spain
5. Universidad de La Laguna, Departamento de Astrofísica, E-38206 La Laguna, Tenerife, Spain
6. Department of Physics & Astronomy, University of Utah, Salt Lake City, UT 84112, USA
7. New Mexico State University, Las Cruces, NM 88003, USA
8. Department of Astronomy and Center for Cosmology and AstroParticle Physics, Ohio State University, Columbus, OH, USA
9. University of Texas at Austin, McDonald Observatory, Fort Davis, TX 79734, USA
10. Department of Physics, Universidad Andres Bello, 700 Fernandez Concha, Chile
11. Departamento de Astronomía, Casilla 160-C, Universidad de Concepción, Concepción, Chile
12. Instituto de Astronomía y Ciencias Planetarias, Universidad de Atacama, Copayapu 485, Copiapó, Chile
13. Observatoire de Besançon, Institut Utinam, CNRS UMR 6213, Université Bourgogne-Franche-Comté, OSU THETA Franche-Comté, BP 1615, 25010 Besançon Cedex, France