1. Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo. Postal 106, Ensenada, B.C. 22800, Mexico
2. Instituto de Astrofísica de Andalucía (IAA-CSIC), Glorieta de la Astronomía S/N, Granada 18008, Spain
3. Instituto de Astronomía y Meteorología, CUCEI, Universidad de Guadalajara, Av. Vallarta 2602, Arcos Vallarta, Guadalajara 44130, Mexico
4. Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, Penteli, Athens 15236, Greece
5. Jodrell Bank Centre for Astrophysics, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
6. Laboratory for Space Research, University of Hong Kong, Pokfulam Road, Hong Kong
7. Faculty of Computer Science and Information Technology, Universiti Malaysia Sarawak, Sarawak 94300, Malaysia
8. Department of Physics & Astronomy, University College London, Gower St, London WC1E 6BT, UK
9. Instituto de Radioastronomía y Astrofísica, UNAM, Campus Morelia, C.P. 58089, Morelia, Mexico
10. Department of Physics, The University of Hong Kong, Chong Yuet Ming Physics Building Pokfulam Road, Hong Kong
11. GRANTECAN, Cuesta de San José s/n, E-38712, Breña Baja, La Palma, Spain
12. Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife, Spain
13. School of Physics, Bristol University, Tyndall Avenue, Bristol, BS8 1TL, UK