1. Department of Physics, George Washington University , 725 21st Street NW, Washington, DC 20052 , USA
2. Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Dr, Pasadena, CA 91109 , USA
3. USRA , 425 3rd Street SW, Suite 950, Washington, DC 20024 , USA
4. Instituto de Astrofisica de Andalucia, Glorieta de la Astronomia , E-18008 Granada , Spain
5. INAF, Osservatorio Astronomico di Brera , Via E Bianchi 46, I-23807 Merate (LC) , Italy
6. INFN – Sezione di Milano-Bicocca , piazza della Scienza 3, I-20126 Milano (MI) , Italy
7. INAF IASF-Milano , Via Alfonso Corti 12, I-20133 Milano , Italy
8. School of Physics and Astronomy, University of Leicester , University Rd, Leicester LE1 7RH , UK
9. Department of Astrophysics/IMAPP, Radboud University , PO Box 9010, NL-6500 GL, Nijmegen , the Netherlands
10. Space Telescope Science Institute , 3700 San Martin Dr, Baltimore, MD 21218 , USA
11. Department of Physics & Astronomy, Clemson University , Kinard Lab of Physics, Clemson, SC 29634 , USA
12. Astrophysics Research Center of the Open University (ARCO), The Open University of Israel , P.O Box 808, Ra’anana 4353701 , Israel
13. Department of Natural Sciences, The Open University of Israel , P.O Box 808, Ra’anana 4353701 , Israel
14. Department of Physics & Astronomy, University of Pennsylvania , 209 S. 33rd Street, Philadelphia, PA 19104 , USA