1. School of Physics and Astronomy, University of Southampton , University Road, Southampton SO17 1BJ , UK
2. Centre for Extragalactic Astronomy, Department of Physics, Durham University , South Road, Durham DH1 3LE , UK
3. Department of Physics, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL , UK
4. INAF – Osservatorio Astronomico di Capodimonte , Salita Moiariello 16, I-80131 Napoli , Italy
5. Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, PL-00-478 Warszawa , Poland