Affiliation: | (1) Massachusetts Institute of Technology, Physics Department, Center for Space Research, 02139 Cambridge, MA, USA;(2) Astronomical Institute Anton Pannekoek, University of Amsterdam, The Netherlands;(3) Center for High Energy Astrophysics, Kruislaan 403, 1098 Amsterdam, SJ, The Netherlands;(4) Institute of Space and Astronautical Sciences, 3-1-1 Yoshinodai, 229 Sagamihara-shi, Japan;(5) Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Rd., 60208 Evanston, IL, USA |