[1] Acad Sinica, Inst Astron & Astrophys, Taipei 10617, Taiwan
[2] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA
[3] Osserv Astron Trieste, INAF, I-34143 Trieste, Italy
[4] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
[5] CALTECH, Cahill Ctr Astron & Astrophys, Pasadena, CA 91125 USA
[6] Space Telescope Sci Inst, Baltimore, MD 21208 USA
[7] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
[8] Osservatorio Astron Bologna, INAF, I-40127 Bologna, Italy
[9] Ist Nazl Fis Nucl, Sez Bologna, I-40127 Bologna, Italy
[10] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA
[11] CSIC, Inst Astrofis Andalucia, E-18008 Granada, Spain
[12] Univ Sternwarte, D-81679 Munich, Germany
[13] Max Planck Inst Extraterr Phys, D-85748 Garching, Germany
[14] Osserv Astron Capodimonte, INAF, I-80131 Naples, Italy
[15] Ikerbasque Basque Fdn Sci, E-48011 Bilbao, Spain
[16] Univ Copenhagen, Niels Bohr Inst, Dark Cosmol Ctr, DK-2100 Copenhagen, Denmark
[17] Ohio State Univ, Ctr Cosmol & Astro Particle Phys, Columbus, OH 43210 USA
[18] Ohio State Univ, Dept Phys, Columbus, OH 43210 USA
[19] Siena Coll, Dept Phys & Astron, Loudonville, NY 12211 USA
[20] Univ Ferrara, I-44122 Ferrara, Italy