High resolution millimeter imaging of the proto-planetary nebula He 3-1475^*

¹ Physics Department, New York University, 4 Washington Place, New York, NY 10003, USA
² IGN Observatorio Astronómico Nacional, Apartado 1143, 28800 Alcalá de Henares, Spain
³ Observatoire de Grenoble, BP 53X, 38041 Grenoble Cedex, France
⁴ CFHT, PO Box 1597, Kamuela, HI 96743, USA
⁵ Institut d'Astrophysique Spatiale, Université de Paris XI, 91405 Orsay Cedex, France

Corresponding author: P. J. Huggins, patrick.huggins@nyu.edu

Received: 1 August 2003
Accepted: 20 October 2003

Abstract

We report high resolution (1´´–2´´) imaging of the CO 2–1 line and the millimeter continuum in the proto-planetary nebula He 3-1475. The observations reveal the presence of a massive (~ ) envelope of molecular gas around the origin of the remarkable bipolar jet system seen in optical images with the HST. The CO kinematics are well modeled by an expanding, bi-conical envelope: the prominent, high-velocity () wings seen in single-dish CO spectra arise where the sides of the bi-cones are projected along the line of sight. The continuum is detected at 1.3 mm and 2.6 mm and is due to thermal emission from warm ( K) circumstellar dust. The structure, kinematics, and expansion time of the envelope provide strong evidence for entrainment of the molecular gas by the high velocity jets. The observations support an evolutionary scenario in which a period of enhanced mass loss by the central star is followed by the development of the bipolar jets which burst through the molecular envelope. The jet-envelope interactions play a crucial role in shaping the subsequent ionized nebula.