Astronomy & Astrophysics manuscript no. APEX_CO_ArXiv c ESO 2018 November 8, 2018 Opening PANDORA’s box: APEX observations of CO in PNe L. Guzman-Ramirez1; 2, A. I. Gómez-Ruíz3, H. M. J. Boffin4, D. Jones5; 6, R. Wesson7, A. A. Zijlstra8; 9, C. L. Smith10, and Lars-Ake˚ Nyman2; 10 1 Leiden Observatory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands e-mail:
[email protected] 2 European Southern Observatory, Alonso de Córdova 3107, Santiago, Chile 3 CONACYT Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis E. Erro 1, 72840 Tonantzintla, Puebla, México 4 European Southern Observatory, Karl-Schwarzschild-str. 2, D-85748 Garching, Germany 5 Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife, Spain 6 Departamento de Astrofísica, Universidad de La Laguna, E-38206 La Laguna, Tenerife, Spain 7 Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK 8 Jodrell Bank Centre for Astrophysics, University of Manchester, Manchester, UK 9 Department of Physics & Laboratory for Space Research, University of Hong Kong, Pok Fu Lam Road, Hong Kong 10 Centre for Research in Earth and Space Sciences, York University, 4700 Keele Street, Toronto, ON, M3J 1P3, Canada 11 Joint ALMA Observatory, Alonso de Córdova 3107, Vitacura, Santiago, Chile Received xx, 2018; accepted xx, 2018 ABSTRACT Context. Observations of molecular gas have played a key role in developing the current understanding of the late stages of stellar evolution. Aims. The survey Planetary nebulae AND their cO Reservoir with APEX (PANDORA) was designed to study the circumstellar shells of evolved stars with the aim to estimate their physical parameters.