| Affiliation: | (1) Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL, 60637, U.S.A.;(2) Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA, 02138, U.S.A;(3) Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL, 60637, U.S.A.;(4) Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA, 02138, U.S.A.;(5) Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL, 60637, U.S.A.;(6) Dipartimento di Scienze Fisiche e Astronomiche, Sezione di Astronomia, Università di Palermo, Piazza del Parlamento 1, I-90134 Palermo, Italy |
