Thomas Berlok

My name is Thomas Berlok and I am a postdoc at the Leibniz-Institute for Astrophysics Potsdam (AIP) in Germany. I am part of the research section Cosmology and High-energy Astrophysics which is lead by Christoph Pfrommer.
I moved to Berlin in 2017 after finishing my PhD in the Theoretical Astrophysics Group at the University of Copenhagen (my advisors were Martin Pessah, Tobias Heinemann and Troels Haugbølle).

My research focuses mostly on astrophysical fluid dynamics and plasma astrophysics. In terms of astrophysical systems, my work so far has primarily been on the dynamics of the intracluster medium in galaxy clusters and on cold streams feeding galaxies with fuel for star formation in the early universe (see my publication list below).

I use computer simulations for much of my work and I am interested in the underlying numerical methods as well as scientific computing in general. I am the main developer of Psecas (Pseudo-Spectral Eigenvalue Calculator with an Automated Solver, see code on Github) and a Braginskii viscosity implementation in the moving mesh code Arepo. During my PhD studies my advisors and I also developed a 2D hybrid-kinetic code for studying ions in collisionless plasmas (this remains unpublished but details can be found in my PhD thesis which can be downloaded here).

Publications

My publications can be found on ADS or via the links below:

Comoving MHD waves

Thomas Berlok, submitted to MNRAS
Hydromagnetic waves in an expanding universe - cosmological MHD code tests using analytic solutions

Suppressed heat conductivity

Berlok, Quataert, Pessah & Pfrommer, 2021, MNRAS, stab832
Suppressed heat conductivity in the intracluster medium: implications for the magneto-thermal instability

Braginskii viscosity in Arepo

Berlok, Pakmor & Pfrommer, 2020, MNRAS, stz3115
Braginskii viscosity on an unstructured, moving mesh accelerated with super-time-stepping

Magnetized cold streams

Berlok & Pfrommer, 2019, MNRAS, stz2347
The impact of magnetic fields on cold streams feeding galaxies

Watch animations of figure 4 and 5.

The Kelvin-Helmholtz Instability

Berlok & Pfrommer, 2019, MNRAS, 485, 908
On the Kelvin-Helmholtz instability with smooth initial conditions - Linear theory and simulations.

Psecas can be downloaded on Github.

PhD thesis 2017

Title: Weakly Collisional and Collisionless Astrophysical Plasmas
Supervisors: Martin E. Pessah, Troels Haugboelle and Tobias Heinemann.

Watch an animation of the firehose instability.

Quasi-global simulations of the ICM

Berlok & Pessah, 2016, ApJ, 833, 2.
On Helium Mixing in Quasi-global Simulations of the Intracluster Medium.

Watch animation of figure 5.

Local simulations of the ICM

Berlok & Pessah, 2016, ApJ, 824, 32.
Local Simulations of Instabilities Driven by Composition Gradients in the ICM.

Watch animation of figure 7.

Stability analysis of the ICM

Berlok & Pessah, 2015, ApJ, 813, 22.
Plasma Instabilities in the Context of Current Helium Sedimentation Models:
Dynamical Implications for the ICM in Galaxy Clusters.