[1] San Diego State Univ, Dept Astron, San Diego, CA 92182 USA
[2] Observ Carnegie Inst Sci, Pasadena, CA 91101 USA
[3] Las Campanas Observ, Carnegie Observ, La Serena 601, Chile
[4] Univ Tokyo, Inst Phys & Math Universe, Kashiwa, Chiba 2778583, Japan
[5] Stockholm Univ, Oskar Klein Ctr, Dept Astron, S-10691 Stockholm, Sweden
[6] Univ Copenhagen, Niels Bohr Inst, Dark Cosmol Ctr, Copenhagen Osterbro 2100, Denmark
[7] Univ Chile, Dept Astron, Santiago, Chile
[8] Texas A&M Univ, Dept Phys & Astron, George P & Cynthia Woods Mitchell Inst Fundamenta, College Stn, TX 77843 USA