¹ Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802
² Institute for Advanced Study, Princeton, NJ 08540
³ Princeton University Observatory, Princeton, NJ 08544
⁴ Departamento de Astronomía y Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile
⁵ Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510
⁶ Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180
⁷ Max-Planck-Institut für extraterrestrische Physik, Geissenbachstrasse 1, D-85741 Garching, Germany
⁸ Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195
⁹ Department of Physics, University of Cincinnati, P.O. Box 210011, Cincinnati, OH 45221
¹⁰ Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637
¹¹ Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349-0059
¹² Department of Astronomy, California Institute of Technology, Pasadena, CA 91125
¹³ Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile
¹⁴ Department of Physics and Astronomy, University of Pittsburgh, 3941 O'Hara Street, Pittsburgh, PA 15260
¹⁵ Department of Physics and Astronomy, Johns Hopkins University, 3701 University Drive, Baltimore, MD 21218
¹⁶ Department of Physics of Complex Systems, Eötvös University, Pázmáy Péter sétány 1/A, H-1117 Budapest, Hungary
¹⁷ Department of Astronomy and Research Center for the Early Universe, School of Science, University of Tokyo, Mitaka, Tokyo 181-0015, Japan
¹⁸ Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, 2778582, Japan
¹⁹ US Naval Observatory, 3450 Massachusetts Avenue, NW, Washington, DC 20392-5420
²⁰ Remote Sensing Division, Code 7215, Naval Research Laboratory, 4555 Overlook Avenue, SW, Washington, DC 20375
²¹ Enrico Fermi Institute, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637
²² Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QJ, UK
²³ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218
²⁴ Royal Observatory, Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
²⁵ US Naval Observatory, Flagstaff Station, P.O. Box 1149, Flagstaff, AZ 86002-1149
²⁶ Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15232