Affiliation: | Physics Department and Astronomical Observatory, University of Perugia, via Pascoli, 06123 Perugia, Italy;INFN, Perugia Section, via Pascoli, 06123 Perugia, Italy;Metsähovi Radio Observatory, Helsinki University of Technology, 02540 Kylmälä, Finland;Department of Astronomy, Dennison Bldg, University of Michigan, Ann Arbor, MI 48109, USA |