1. Astrophysics Research Institute, Liverpool John Moores University , 146 Brownlow Hill, Liverpool L3 5RF , UK
2. Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal , 4, E-20018 Donostia-San Sebastián, Guipuzkoa , Spain
3. IKERBASQUE, Basque Foundation for Science , E-48013 Bilbao , Spain
4. ICREA , Pg. Lluís Companys 23, E-08010 Barcelona , Spain
5. Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona (IEEC-UB) , Martí i Franquès 1, E-08028 Barcelona , Spain
6. Anton Pannekoek Institute for Astronomy , Science Park 904, NL-1098XH Amsterdam , the Netherlands
7. Institute of Astronomy , KU Leuven, Celestijnenlaan 200D, B-3001 Leuven , Belgium
8. Institute for Physics and Astronomy, University of Potsdam , Karl-Liebknecht-Str. 24/25, D-14476 Potsdam , Germany
9. Institute for Astrophysics, Georg-August-University Göttingen , Friedrich-Hund-Platz 1, D-37077 Göttingen , Germany
10. The Oskar Klein Centre, Department of Astronomy, Stockholm University , AlbaNova, SE-106 91 Stockholm , Sweden
11. Department of Astronomy and Physics, Saint Mary’s University , 923 Robie Street, Halifax, NS B3H 3C3 , Canada