[1] Osservatorio Astron Bologna, INAF, I-40127 Bologna, Italy
[2] Inst Astrofis Canarias, San Cristobal la Laguna 38205, Spain
[3] Alma Mater Studiorum Univ Bologna, Dipartimento Astron, I-40127 Bologna, Italy
[4] ESA, European Space Astron Ctr ESAC, Madrid 28692, Spain
[5] Max Planck Inst Extraterr Phys, D-85748 Garching, Germany
[6] CEA Saclay, Serv Astrophys, F-91191 Gif Sur Yvette, France
[7] Univ Paris Diderot, CEA Saclay, Lab AIM, CEA,DSM,CNRS,IRFU,Serv Astrophys, F-91191 Gif Sur Yvette, France
[8] Osserv Astron Trieste, INAF, I-34143 Trieste, Italy
[9] Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy
[10] Univ Trieste, Dipartimento Fis, Sez Astron, I-34127 Trieste, Italy
[11] Space Telescope Sci Inst, Baltimore, MD 21218 USA
[12] Univ Tokyo, IPMU, Kashiwa, Chiba 2778568, Japan
[13] ETH, Inst Astron, CH-8093 Zurich, Switzerland
[14] Univ Toulouse, CNRS, Lab Astrophys Toulouse Tarbes, F-31400 Toulouse, France
[15] Univ Aix Marseille, Lab Astrophys Marseille, F-13388 Marseille 13, France
[16] European So Observ, D-85748 Garching, Germany
[17] Osserv Astron Padova, INAF, I-35122 Padua, Italy
[18] IASF Milano, INAF, I-20133 Milan, Italy
[19] Univ Groningen, Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands
[20] Osserv Astron Brera, INAF, I-20121 Milan, Italy
[21] CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain