1. MTA-Eötvös University Lendület Hot Universe Research Group, Pázmány Péter sétány 1/A, Budapest, 1117, Hungary
2. INAF, Osservatorio Astronomico di Trieste, via Tiepolo 11, I-34131, Trieste, Italy
3. Department of Physics, University of Michigan, 450 Church St., Ann Arbor, MI 48109, USA
4. Dipartimento di Fisica dell’ Università di Trieste, Sezione di Astronomia, via Tiepolo 11, I-34131 Trieste, Italy
5. Institute of Physics, Eötvös University, Pázmány P. s. 1/A, Budapest 1117, Hungary
6. SRON Netherlands Institute for Space Research, Sorbonnelaan 2, NL-3584 CA Utrecht, the Netherlands
7. Department of Theoretical Physics and Astrophysics, Faculty of Science, Masaryk University, Kotlářská 2, Brno, 611 37, Czech Republic
8. School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
9. Department of Astrophysical Sciences, Princeton University, 4 Ivy Ln, Princeton, NJ 08544, USA
10. INFN, Instituto Nazionale di Fisica Nucleare, Trieste, Italy
11. Departamento de Astronomía y Astrofísica, Universidad de Valencia, c/Dr. Moliner, 50, E-46100 Burjassot, Valencia, Spain
12. Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia