An ALMA View of the Complex Circumstellar Environment of the Post-AGB Object HD 101584

Paper in proceeding, 2015

We use (CO)-C-12, (CO)-C-13, and (CO)-O-18 J = 2-1 lines and 1.3 mm continuum ALMA observations to study the circumstellar evolution of the binary HD 101584, a post-AGB star and a low-mass companion, which is-most likely a post-common envelope-evolution system. It is inferred that the circumstellar medium has a bipolar hour-glass structure, seen almost pole-on, formed by an energetic, approximate to 150 km s(-1), jet. Significant amount of material resides in an unresolved central region. It is proposed that the circumstellar morphology is related to an event which took place approximate to 500 yr ago, possibly a capture event where the companion spiraled in towards the AGB star. However, the kinetic energy of the accelerated gas exceeds the released orbital energy. Hence, the observed phenomenon does not match current common-envelope scenarios, and another process must augment, or even dominate, the ejection process.