1. INAF-Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125, Florence, Italy
2. Centro de Astrobiología (CSIC−INTA). Ctra de Ajalvir, km. 4, Torrejón de Ardoz, E-28850 Madrid, Spain
3. School of Physics and Astronomy, Queen Mary University of London, Mile End Road, E1 4NS London, United Kingdom
4. European Southern Observatory (ESO), Alonso de Córdova 3107, Vitacura, 763 0355 Santiago, Chile
5. Joint ALMA Observatory, Alonso de Córdova 3107, Vitacura, Santiago, Chile
6. Observatorio Astronómico de Quito, Escuela Politécnica Nacional, Av. Gran Colombia S/N, Interior del Parque La Alameda, 170136 Quito, Ecuador
7. Department of Astronomy, University of Maryland, College Park, ND 20742-2421, USA
8. Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany