1. Centre for Extragalactic Astronomy, Department of Physics, Durham University , Durham DH1 3LE , UK
2. Institute for Astronomy, University of Edinburgh, Royal Observatory , Blackford Hill, Edinburgh EH9 3HJ , UK
3. Department of Physics, Drexel University , 32 S. 32nd Street, Philadelphia, PA 19104 , USA
4. Institute for Computational Cosmology, Department of Physics, Durham University , South Road, Durham DH1 3LE , UK
5. School of Mathematics, Statistics and Physics, Newcastle University , Newcastle upon Tyne, NE1 7RU , UK
6. European Southern Observatory , Karl-Schwarzschild-Str. 2, D-85748 Garching bei München , Germany
7. INAF-IRA , Via P. Gobetti 101, I-40129 Bologna , Italy
8. Physics Department, University of Johannesburg , 5 Kingsway Ave, Rossmore, Johannesburg 2092 , South Africa