The astrochemistry of dying stars

Astrochemistry is an interdisciplinary field that brings together astronomy, physics, and chemistry. Despite the hostile conditions, these environments are rich in molecules: more than 330 interstellar and circumstellar molecules have been detected so far. These molecules open up detailed windows to the physical conditions of the environment in which they are found.

During the asymptotic giant branch (AGB) phase near the end of their lives, stars like our Sun lose their outer envelope via a stellar outflow to the interstellar medium (ISM). AGB outflows are rich astrochemical laboratories: close to 100 molecules have been detected so far, along with some 15 types of newly formed dust. Besides their chemical complexity, AGB outflows also show dynamical complexity. Large-scale density structures, such as spirals and disks, are ubiquitously observed and thought to be caused by binary interaction with a (sub)stellar companion.

To keep up with the wealth of high-resolution observations, the standard spherically symmetric chemical model has been adapted. I will talk about how chemical models can help us interpret the dynamics of the outflow and where they fall short in reproducing the observations, indicating that new physics or chemistry needs to be included.