Star & Planet Formation
The detection of the first exoplanet in the mid-1990ies opened a whole new chapter in modern astrophysics - and today more than a thousand exoplanets are known.
These many exoplanets raise a number of questions about their formation - for example, how common are "solar systems" like our own? In order to understand the diversity of exoplanet systems, and even to understand the formation of our own Solar System, we need a detailed understanding of the combined process by which stars and planets are formed.
Today we have a reasonably well-established overall picture of the fundamental physical mechanisms that lead to the formation of stars and planets, but still many aspects remain unclear - in particular, concerning the very first and last stages of this process. Star formation initiates through the fragmentation of molecular clouds which leads to dense pre-stellar cores. The following core contraction and subsequent growth through accretion leads to the formation of stars.
Young protostars are surrounded by a dense envelope of dust and gas. Accretion occurs through a disk, while the accumulating angular momentum is releived through powerful jets. Interactions between these different components along with the radiation from the forming star excite atoms and molecules, heats up the dust and ignites a series of complex chemical reactions. On the other end, when a star is formed and accretion has ceased, coagulation of the remaining disk material leads to the growth of solids. The evolution of dust grains in protoplanetary disks play a fundamental role in the formation and early evolution of planetary systems
Researchers in our group are aiming to understand the physical and chemical processes related to the formation of stars and planets. To this we use state-of-the-art observing facilities such as the Herschel Space Observatory and the Atacama Large Millimeter Array. In addition, we develop and use complex numerical physical, chemical and radiative transfer models that can realistically describe the processes taking place during star-formation.