Affiliation: | (1) Institute for Space Studies, Goddard Space Flight Center, NASA, New York, N.Y., USA;(2) Smithsonian Astrophysical Observatory, Cambridge, Mass., USA;(3) Belfer Graduate School of Science, Yeshiva University, New York, N.Y., USA;(4) Institute for Space Studies, Goddard Space Flight Center, NASA, New York, N.Y., USA;(5) Present address: Belfer Graduate School of Science, Yeshiva University, New York, N.Y., USA;(6) Present address: Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, Calif., USA |