Structural dynamics of PAH molecules upon energetic photon or ion interactions

Polycyclic aromatic hydrocarbons (PAHs) form a special family of molecules. PAHs consist of rings of carbon atoms and have hydrogen atoms at the edges. PAHs have a planar shape and are highly stable molecules. This molecules are everywhere, for instance in exhaust gasses and on the barbecue.
In space PAHs influence important processes such as star formation. Furthermore, they emit infrared light, which is invisible for the human eye, but visible with special telescopes. In this way they form our barometers in space. The infrared light depends on the local conditions in the environment of the PAH: the PAH family forms a collection of billions of nanoscopic measurement tools in space.
The existence of PAHs in space is surprising, given the harsh conditions in most of the interstellar regions. The central question in this thesis is: How do PAHs survive the harsh space weather? This question is addressed by means of experimental techniques in which a small piece of space is reproduced in the lab. The behavior of the PAHs in this small space-like environment is analyzed precisely.
The experiments identify how PAHs respond to external influences such as ions and UV or Röntgen light and how PAHs survive the space weather. They wear a “raincoat” of hydrogen atoms, which are everywhere abundant in space.