Whether by bike or on skis: outdoors is key!

April 24, 2026

Eric Rohr came to MPA to benefit from the numerical and scientific expertise here, and was not expecting the full programme of social events.

What are your current research interests at the MPA?

Simulation of gas temperature in a galaxy cluster, ranging from green and yellow to red. — This image shows the gas temperature in an example proto-cluster at redshift z=4 from the TNG-Cluster simulation. The inner black circle denotes the approximate boundary between the brightest cluster galaxy and the intracluster medium. The outer black circle shows the approximate boundary between the intracluster and the intergalactic medium. Many of the astrophysical phenomena responsible for either the creation, destruction, or survivability of cool gas in the intracluster medium are interconnected.

Image Credit: Rohr et al. 2025

This image shows the gas temperature in an example proto-cluster at redshift z=4 from the TNG-Cluster simulation. The inner black circle denotes the approximate boundary between the brightest cluster galaxy and the intracluster medium. The outer black circle shows the approximate boundary between the intracluster and the intergalactic medium. Many of the astrophysical phenomena responsible for either the creation, destruction, or survivability of cool gas in the intracluster medium are interconnected.

Image Credit: Rohr et al. 2025

I am interested in various aspects of galaxy formation and evolution, hierarchical structure formation and the use of numerical techniques in magneto-hydrodynamic simulations. Specifically, I study the role of galactic feedback processes – namely, feedback from massive stars and black holes – in shaping the thermodynamic structure of the surrounding gas. I also consider how this affected gas can be used as fuel for star formation and black hole accretion. Through various projects and collaborations, each focusing on different physical and temporal scales, I am tackling these problems from different perspectives.

One overarching theme emerges: the evolution of multiphase gas studied using hydrodynamic simulations. For example, I study how high-redshift black holes can grow quickly enough to match those observed by the James Webb Space Telescope, how galaxy mergers in the early universe can trigger periods of intense star formation, and how cold gas evolves in the tails of jellyfish galaxies.

What brought you to MPA in particular?

If you are interested in studying galaxy evolution using hydrodynamic simulations, specifically simulations based on the moving-mesh code AREPO, then there is nowhere in the world better than MPA; the numerical and scientific expertise here is unparalleled. Furthermore, the computational resources available at MPA and MPCDF enable me to run and analyse almost all of the simulations I could wish for. Lastly, being able to connect these theoretical results and predictions with the larger-scale cosmology and smaller-scale stellar departments, as well as the observations from the galaxies department, promotes a rich exchange of ideas and methods in my own research and that of others.

What would you be doing if you weren’t an astrophysicist?

Outside of astrophysics, I can see two potential paths: data science and the service industry. After programming and analysing big data from chaotic and seemingly random simulations for so many years, I have often wondered how these skills could be applied to other aspects of my life.

I would like to predict sporting performances and outcomes based on biometric data (e.g. estimating power output from cyclists without a power meter), improve “shuffle” algorithms to help music listeners find new music or enhance their listening experience, and forecast market changes based on upcoming edits to the virtual economies in massively multiplayer online games (MMOs).

On the other hand, I love interacting with people and brightening their days, which is a fundamental goal of the service industry. I’ve often romanticised the idea of working as a coffee roaster or barista, a yoga instructor, or an adventure tour guide, leading multi-day bike or hike tours, for example.

How do you spend your time outside the institute?

Two skiers in a snowy mountain valley under a clear sky. — The picture shows Eric Rohr ski touring with a friend in Tyrol, Austria in 2026. The background shows the Lareinferner glacier, the Heidelbergerspitze (2963m), the Lareinfernerspitze (3009m), and the Fluchthorn (3396 m). The yellowish tint is due to Sahara dust from a recent sandstorm.

Image Credit: N. Evert Nasedkin

The picture shows Eric Rohr ski touring with a friend in Tyrol, Austria in 2026. The background shows the Lareinferner glacier, the Heidelbergerspitze (2963m), the Lareinfernerspitze (3009m), and the Fluchthorn (3396 m). The yellowish tint is due to Sahara dust from a recent sandstorm.

Image Credit: N. Evert Nasedkin

Like a dog, if I don’t get enough time to run around outside, I get antsy. I really enjoy running, hiking, cycling, swimming, basketball, volleyball, Spikeball and pretty much any other activity that lets me burn off energy. The best solution is to bike to work, and luckily the English Garden and its trails offer an idyllic daily commute through the forest next to the Isar.

More recently, ski touring and bike packing (multi-day bike trips where all luggage, including the tent and kitchen utensils, is carried on the bike) have become my two favourite holiday activities. In fact, I’m excited for my upcoming two-week bikepacking trip, which starts and ends in Rome, Italy. Outside of sports, I enjoy cooking with friends, going to live music events and playing card and board games. My two favourites are Durak and Catan.

What do you particularly enjoy about working at MPA?

I’ve already talked about MPA’s high scientific calibre, which was certainly my first major takeaway when I started here: I love being able to attend the morning coffee and discuss recent papers on arXiv, current research problems and new numerical methods to be implemented. But this only scratches the surface of the social life at MPA, which I wasn’t expecting.

From ballroom dance classes to movie nights to full-on parties, MPA and neighbouring institutes have curated a full programme of social events where everyone is welcome. Finally, it would be remiss not to mention the legendary common room when discussing the social life at MPA. I would go into more detail, but the first rule about the common room is not to talk about the common room!