I am professor for theoretical astrophysics at Heidelberg University. My research activities focus on the formation of stars at present days and in the early universe, on the dynamics of the interstellar medium, on astrophysical turbulence, and on the development of numerical methods for computational astrophysics.

For an overview of my curriculum vitae follow this LINK.

For my website at the Center for Astronomy at Heidelberg University follow this LINK.

I recently received an ERC synergy grant together with Patrick Hennebelle (CEA, Saclay), Sergio Molinari (INAF, Rome), and Leonardo Testi (ESO, Garching). More information is found on this LINK.

Current Research Highlight

November 2019: Radiative Transfer with POLARIS. II. Modeling of Synthetic Galactic Synchrotron Observations

Reißl, S., Brauer, R., Klessen, R. S., Pellegrini, E. W.  (ApJ, 885, 15, 2019)

Synthetic synchrotron emission at 734.8 mm from model galaxy computed with Polaris.

We present an updated version of POLARIS, a well-established code designated for dust polarization and line radiative transfer (RT) in arbitrary astrophysical environments. We extend the already available capabilities with a synchrotron feature for polarized emission. Here, we combine state-of-the-art solutions of the synchrotron RT coefficients with numerical methods for solving the complete system of equations of the RT problem, including Faraday rotation (FR) as well as Faraday conversion (FC). We validate the code against Galactic and extragalactic observations by performing a statistical analysis of synthetic all-sky synchrotron maps for positions within the Galaxy and for extragalactic observations. For these test scenarios we apply a model of the Milky Way based on sophisticated magnetohydrodynamic simulations and population synthesis post-processing techniques. We explore different parameters for modeling the distribution of free electrons and for a turbulent magnetic field component. We find that a strongly fluctuating field is necessary for simulating synthetic synchrotron observations on small scales, we argue that FR alone can account for the depolarization of the synchrotron signal, and we discuss the importance of the observer position within the Milky Way. Altogether, we conclude that POLARIS is a highly reliable tool for predicting synchrotron emission and polarization, including FR in a realistic galactic context. It can thus contribute to a better understanding of the results from current and future observational missions.

Earlier Research Highlights

For the research highlights of previous months, follow this LINK.

Funding Sources