1. Center for Astrophysics | Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA
2. Black Hole Initiative at Harvard University , 20 Garden Street, Cambridge, MA 02138, USA
3. Department of Physics, University of Illinois at Urbana-Champaign , 1110 West Green Street, Urbana, IL 61801, USA
4. Department of Astronomy, University of Illinois at Urbana-Champaign , 1002 West Green Street, Urbana, IL 61801, USA
5. CCS-2, Los Alamos National Laboratory , PO Box 1663, Los Alamos, NM 87545, USA