1. Department of Physics, Engineering Physics & Astronomy, Queens University , Kingston, ON K7L 3N6, Canada
2. Department of Astronomy, University of Massachusetts , LGRT-B 619E, 710 North Pleasant Street, Amherst, MA 01003-9305, USA
3. Department of Physics & Astronomy, University of Calgary , 834 Campus Place N. W., 2500 University Drive N W, Calgary, AB T2N 1N4, Canada
4. Faculty of Physics and Astronomy, Ruhr University Bochum , AIRUB D-44780, Germany
5. Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS , UMR 7550, 11 rue de l’Université, F-67000 Strasbourg, France
6. Department of Physics and Astronomy, University of Manitoba , Winnipeg, MB R3T 2N2, Canada