Affiliation: | (1) Steward Observatory, University of Arizona, Tucson, AZ 85721, USA;(2) KOSMA, I. Phys. Institut, Universit?t zu K?ln, 50937 K?ln, Germany;(3) Astronomy Dep., University of Massachusetts, Amherst, MA 01003, USA;(4) ECE Dep., University of Virginia, Charlottesville, VA 22904, USA;(5) Caltech, MS 320-47, Pasadena, CA 91125, USA;(6) Caltech, MS 136-93, Pasadena, CA 91125, USA |