1. Center for Computational Astrophysics, Flatiron Institute , 162 Fifth Avenue, New York, NY 10010, USA
2. Department of Physics, University of Connecticut , 196 Auditorium Road, U-3046, Storrs, CT 06269-3046, USA
3. Department of Physics and Astronomy and CIERA, Northwestern University , Evanston, IL 60208, USA
4. Department of Astronomy, Van Vleck Observatory, Wesleyan University , 96 Foss Hill Drive, Middletown, CT 06459, USA
5. Columbia Astrophysics Laboratory, Columbia University , 550 West 120th Street, New York, NY 10027, USA
6. Department of Physics & Astronomy, University of California , Davis, CA 95616, USA
7. TAPIR, California Institute of Technology, MC 350-17, Pasadena, CA 91125, USA
8. Department of Physics and Astronomy, Pomona College , Claremont, CA 91711, USA
9. Black Hole Initiative, Harvard University , 20 Garden St, Cambridge, MA 02138, USA