The position is part of the ERC Starting Grant ReMMU (Resolving the Multiscale, Multiphase Universe) in the group of Dr. Max Gronke at the Astronomisches Rechen-Institut (ARI), part of the Zentrum für Astronomie der Universität Heidelberg (ZAH). ReMMU aims to overcome the long-standing lack of convergence in cosmological simulations by developing and applying novel multi-fluid models of unresolved gas physics. This position focuses on connecting these models to observations through radiative transfer in multiphase media.

At the Astronomisches Rechen-Institut (ARI) of Heidelberg University, the following full-time position (100%) is to be filled from 1 July 2027 (starting date negotiable), fixed-term for two years (with possible extension by a third year):

Postdoctoral Researcher in Theoretical/Computational Astrophysics (f/m/d)

ERC Starting Grant ReMMU: Radiative Transfer in Multiphase Media

Your tasks:

• Independent and collaborative research within ReMMU, connecting multi-fluid models of unresolved gas physics to observations via radiative transfer (RT) in multiphase media
• Research topics include ionizing (Lyman continuum) RT and escape fractions, the epoch of reionization, line transfer, and X-ray line emission
• Construction of synthetic observables and their comparison with observations
• Participation in the group′s research activities and supervision of students
• Dissemination of results through publications and conferences, and collaboration within international projects

Your profile:

• Completed university degree and PhD (or equivalent) in astrophysics, physics, or a closely related field
• Demonstrated experience in radiative transfer, emission line modeling, or related areas of computational astrophysics
• Strong programming and analytical skills
• Ability to work independently and as part of a team in an international research environment
• Experience with hydrodynamical simulations or with observations of the circumgalactic medium is a plus but not required

We offer:

• A vibrant, collaborative environment in the ASGARD group (Astrophysical Gas and Radiation Dynamics, asgard-ari.github.io/
• Close ties across Heidelberg′s strong astrophysics community (ZAH, MPIA, ITA, IWR etc.)
• Access to major HPC resources
• Generous travel and equipment funds

Remuneration is based on salary grade 13 under the TV-L collective agreement. The monthly gross salary for the respective salary grade is determined in accordance with the collective agreement (TV-L Remuneration Schedule) and the applicable assignment to a salary step. The current salary tables for the State of Baden-Württemberg can be found here: lbv.landbw.de/leistungen-und-services/gehaltstabellen.

The position can in principle be filled on a part-time basis.

We look forward to your application. Full consideration will be given to applications received by 10 January 2027. Please send a single PDF file (cover letter, CV, publication list, and a 2-3 page research statement) by e-mail to Dr. Max Gronke (max.gronke@uni-heidelberg.de) with the subject line "ReMMU RT postdoc application". Please arrange for 2-3 letters of reference to be sent to the same address with the subject line "ReMMU RT postdoc letter".

Heidelberg University stands for equal opportunities and diversity. Qualified female candidates are especially invited to apply. Persons with severe disabilities will be given preference if they are equally qualified. Information on job advertisements and the collection of personal data is available at www.uni-heidelberg.de/en/job-market.