Me in the Musée du Louvre. Paris 2019.

(long version)

*2021 MPA Garching Ph. D. Astronomy with Dr. Thorsten Naab
2017 Universität zu Köln M. Sc. Physics with Prof. Dr. Stefanie Walch
2015 Universität zu Köln B. Sc. Physics with Prof. Dr. Stefanie Walch
If you want to build a ship, do not drum up the men to gather wood, divide the work, and give orders. Instead, teach them to yearn for the vast and endless sea.
Antoine de Saint-Exupéry


Word cloud created out of my PhD thesis.

Towards a complete model of the interstellar medium

I am interested in the evolution of the interstellar medium,Time evolution of the gas column density in a simulation with only SNe feedback. galactic outflows and how massive stars shape their environment and regulate star formation with their feedback.
Within the SILCC project,The SILCC project I systematically study the impact of supernovae, stellar winds, ionising UV radiation, cosmic rays and runaway stars on star formation and the capabilities to drive and sustain galactic outflows.
I mainly use the MPI parallel, magneto-hydrodynamics (MHD), 3D adaptive mesh refinement (AMR) code FLASH to carry out my research with high-resolution ISM simulations on high-performance computing (HPC) clusters like SuperMUC-NG.

Star formation rate surface density vs gas surface density of ISM simulations with increasing feedback complexity.

Stratified disk simulation with an initial gas surface density of Σ = 50 M / pc2. The simulation includes stellar feedback in form of type II supernovae, stellar winds, ionising UV radiation, and cosmic rays, as well as a type Ia supernova background, and runaway stars. Shown are the edge-on (top row) and face-on (bottom row) views of the total gas, ionised-, atomic-, and molecular hydrogen column densities. Individual HII regions (3rd panel) from active star clusters are visible. Also shown is the density-weighted column of the magnetic field strength (6th panel) and slices through the centre of the simulation box with temperature (2nd panel) and CR energy density (7th panel). The star-forming galactic ISM is concentrated around the mid-plane. White circles in the 1st and 3rd panels indicate star clusters with different masses. The smallest white circles are individual runaway OB stars. Translucent symbols indicate old star clusters with no active massive stars in them. Stellar feedback generates a highly structured and turbulent multi-phase ISM with all its major thermal and non-thermal components.

Predicting the optical emission line properties of the ISM

Building upon my high-reslution simulations, I am interested in analysing the emission line properties of the simulated interstellar medium. I use the photo-ionisation code Cloudy, combined with self-developed tools, to post-process my simulations and predict the optical line emissionEmission map of various optical emission lines. and infer observable properties via line ratio diagnostics.

BPT diagram of a single HII region
Line ratio diagnostics diagram (BPT diagram, Baldwin et al., 1981) of a single HII region simulated within the SILCC framework.

Remember to look up at the stars and not down at your feet. Try to make sense of what you see and wonder about what makes the universe exist. Be curious. And however difficult life may seem, there is always something you can do and succeed at. It matters that you don't just give up.
Stephen Hawking


Tim-Eric Rathjen
Max-Planck-Institut für Astrophysik
Karl-Schwarzschild-Strasse 1
85748 Garching

+49 89 30000 2009

When I heard the learn’d astronomer, When the proofs, the figures, were ranged in columns before me, When I was shown the charts and diagrams, to add, divide, and measure them, When I sitting heard the astronomer where he lectured with much applause in the lecture-room, How soon unaccountable I became tired and sick, Till rising and gliding out I wander’d off by myself, In the mystical moist night-air, and from time to time, Look’d up in perfect silence at the stars
Walt Whitman