[1] Univ Utrecht, Dept Phys & Astron, NL-3584 CC Utrecht, Netherlands
[2] Deutsches Elektron Synchrotron, D-15735 Zeuthen, Germany
[3] Univ Canterbury, Dept Phys & Astron, Christchurch 1, New Zealand
[4] Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany
[5] Univ Wisconsin, Dept Phys, Madison, WI 53706 USA
[6] Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany
[7] Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA
[8] Vrije Univ Brussel, Dienst ELEM, B-1050 Brussels, Belgium
[9] Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA
[10] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA
[11] Univ Dortmund, Dept Phys, D-44221 Dortmund, Germany
[12] Univ Libre Bruxelles, Fac Sci, B-1050 Brussels, Belgium
[13] Univ Maryland, Dept Phys, College Pk, MD 20742 USA
[14] Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA
[15] Univ Stockholm, Dept Phys, SE-10691 Stockholm, Sweden
[16] Uppsala Univ, Div High Energy Phys, S-75121 Uppsala, Sweden
[17] Univ Mons, B-7000 Mons, Belgium
[18] Univ Ghent, Dept Subatom & Radiat Phys, B-9000 Ghent, Belgium
[19] Univ Wisconsin, Dept Phys, River Falls, WI 54022 USA
[20] Clark Atlanta Univ, CTSPS, Atlanta, GA 30314 USA
[21] So Univ, Dept Phys, Baton Rouge, LA 70813 USA
[22] Univ Wisconsin, Dept Astron, Madison, WI 53706 USA
[23] Max Planck Inst Kernphys, D-69177 Heidelberg, Germany
[24] Chiba Univ, Dept Phys, Chiba 2638522, Japan
[25] Rhein Westfal TH Aachen, Inst Phys 3, D-52074 Aachen, Germany
[26] Humboldt Univ, Inst Phys, D-12489 Berlin, Germany
[27] Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BW, England
[28] Kalmar Univ, Dept Chem & Biomed Sci, S-39182 Kalmar, Sweden
[29] Univ Oxford, Dept Phys, Oxford OX1 3NP, England
[30] Univ Valencia, CSIC, IFIC, Valencia 46071, Spain
[31] Observ Haute Provence, St Michel Observ, F-04870 St Michel, France
[32] MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA
[33] CNR, Area Ric Roma Tor Vergata, Inst Nazl Astrofis, Inst Astrofis Spaziale & Fis Cosmica, I-00133 Rome, Italy
[34] Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA
[35] CALTECH, Caltech Opt Observ, Pasadena, CA 91125 USA
[36] Max Planck Inst Extraterr Phys, D-85748 Garching, Germany
[37] Univ Ferrara, Dept Phys, I-44100 Ferrara, Italy
[38] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[39] Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA
[40] Univ Alaska Anchorage, Dept Phys & Astron, Anchorage, AK 99508 USA
[41] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA
[42] Penn State Univ, Dept Phys, University Pk, PA 16802 USA
[43] Inst Adv Study, Princeton, NJ 08540 USA