ALMA observations of the Red Rectangle, a preliminary analysis^⋆

¹ Observatorio Astronómico Nacional (OAN-IGN), Apartado 112, 28803 Alcalá de Henares, Spain
e-mail: v.bujarrabal@oan.es
² Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 Saint Martin d’Hères, France
³ Observatorio Astronómico Nacional (OAN-IGN), C/ Alfonso XII, 3, 28014 Madrid, Spain
⁴ Instituut voor Sterrenkunde, K.U. Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium
⁵ Centro de Astrobiología (CSIC-INTA), ESAC Campus, 28691 Villanueva de la Cañada, Madrid, Spain
⁶ Centro de Astrobiología (CSIC-INTA), Ctra. M-108, km. 4, 28850 Torrejón de Ardoz, Madrid, Spain
⁷ UJF-Grenoble1/CNRS-INSU, Inst. de Planétologie et d’Astrophysique de Grenoble (IPAG) UMR 5274, 38041 Grenoble, France

Received: 9 July 2013
Accepted: 19 July 2013

Abstract

Aims. We aim to study equatorial disks in rotation and axial outflows in post-AGB objects so as to disclose the formation and shaping mechanisms in planetary nebulae. So far, both disks and outflows have not been observed simultaneously.

Methods. We obtained high-quality ALMA observations of ¹²CO and ¹³CO J = 3−2 and ¹²CO J = 6−5 line emission in the Red Rectangle, the only post-AGB/protoplanetary object for which a disk in rotation has been mapped.

Results. These observations provide an unprecedented description of the complex structure of this source. Together with an equatorial disk in rotation, we find a low-velocity outflow that more or less occupies the region situated between the disk and the optical X-shaped nebula. From our observations and preliminary modeling of the data, we confirm the previously known properties of the disk and obtain a first description of the structure, dynamics, and physical conditions of the outflow.