¹ Kavli Institute for Cosmological Physics, Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637, USA
² Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637, USA
³ School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
⁴ California Institute of Technology, Mail Code 105-24, Pasadena, CA 91125, USA
⁵ Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK
⁶ Space Science Office, VP62, NASA/Marshall Space Flight Center, Huntsville, AL 35812, USA
⁷ Department of Physics, University of Alabama, Huntsville, AL 35812, USA
⁸ Laboratoire d'Astrophysique de Marseilles, OAMP, CNRS-Université Aix-Marseilles, 38 rue Frédéric Joliot-Curie, 13388 Marseilles Cedex 13, France
⁹ Department of Physics, University of Chicago, Chicago, IL 60637, USA
¹⁰ Enrico Fermi Institute, University of Chicago, Chicago, IL 60637, USA
¹¹ Owens Valley Radio Observatory, California Institute of Technology, Big Pine, CA 93513, USA
¹² Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027, USA
¹³ Department of Physics, Columbia University, New York, NY 10027, USA
¹⁴ Department of Astronomy, Columbia University, New York, NY 10027, USA
¹⁵ Jansky Fellow, National Radio Astronomy Observatory.