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 Karl Franzens University Graz

Graz University of Technology 

Physico-chemical processes in planet-forming disks
Peter Woitke
Space Research Institute, Austrian Academy of Sciences, Graz
16:15 - 17:15 Tuesday 08 March 2022 TUG online event

Video: https://tugraz.webex.com/tugraz/j.php?MTID=md84681f5f205fc0fad0a584aaa2d2da7

Planets form in so-called protoplanetary disks. These are astrophysical objects where
the remaining masses of gas and dust after star formation keep on rotating around the
new-born star for a few million years. On this timescale, we believe that micron-sized
dust particles collide with each other to form larger solid bodies of ever increasing size,
finally also attracting the gas via gravitational forces, which eventually creates new
rocky planets and gas giants. The observation of these systems is hence crucial for our
understanding of the formation of planets, and an important step toward the creation
of life.

In my talk, I will demonstrate some basic principles of the modelling of these astronomical
objects, such as the solution of astrochemical rate networks to find the molecular
composition, and the solution of the non-LTE heating and cooling balance to determine the
temperature in the disk. The simulation results are then used to predict a large suite of
different observations, which can be compared to the observational data, for example
continuum fluxes and images, high-resolution molecular line velocity profiles, and
low-resolution infrared spectra. However, each single observation can only reveal a very
limited amount of information about specific properties at particular places in the disks,
so it is mandatory to combine these different observations, based on the insight provided
by the models, in our quest to better understand the true nature of planet-forming disks.