1. University of Maryland Baltimore County, Department of Physics, Maryland
2. NASA/Goddard Space Flight Center, High Energy Astrophysics Science Archive Center, Greenbelt, Maryla
3. Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridg
4. NASA/Goddard Space Flight Center, X-Ray Astrophysics Laboratory, Greenbelt, Maryland
5. Hiroshima University, Higashi-Hiroshima, Hiroshima
6. Universities Space Research Association, Columbia, Maryland