1. Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
2. Black Hole Initiative, Harvard University, 20 Garden Street, Cambridge, MA 02138, USA
3. Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany
4. School of Natural Sciences, Institute for Advanced Study, 1 Einstein Drive, Princeton, NJ 08540, USA
5. NASA Hubble Fellowship Program, Einstein Fellow
6. Instituto de Astrofísica de Andalucía-CSIC, Glorieta de la Astronomía s/n, E-18008 Granada, Spain
7. Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON N2L 2Y5, Canada
8. Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
9. National Biomedical Imaging Center, College of Future Technology, Peking University, Beijing 100871, China
10. Department of Physics & Astronomy, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
11. Lebedev Physical Institute of the Russian Academy of Sciences, Leninsky Prospekt 53, 119991 Moscow, Russia
12. Moscow Institute of Physics and Technology, Institutsky per. 9, 141700 Dolgoprudny, Russia
13. Department of Astronomy, Yale University, New Haven, CT 06511, USA
14. Department of Physics, Yale University, New Haven, CT 06520, USA
15. Department of Physics, Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA