1. Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD, USA
2. Departamento de Ingeniería Eléctrica, Universidad Católica de la Santísima Concepción, Concepción, Chile
3. Department of Physics, Villanova University, Villanova, PA, USA
4. NASA Goddard Space Flight Center, Greenbelt, MD, USA
5. Center for Space Sciences and Technology, University of Maryland, Baltimore, Baltimore, MD, USA
6. Center for Astrophysics, Harvard and Smithsonian, Cambridge, MA, USA
7. Institute of Theoretical Astrophysics, University of Oslo, Oslo, Norway
8. MIT Kavli Institute, Massachusetts Institute of Technology, Cambridge, MA, USA