Jobs

Postdoctoral Position in Astrophysics: Gaia DPAC Software Development

High-Energy Astrophysics Group (GAPHE), University of Liège (ULiège), Belgium

The High-Energy Astrophysics Group (GAPHE) at the University of Liège is seeking a talented and motivated Postdoctoral researcher to take over the development, validation, and maintenance of key work packages from the Gaia Data Processing and Analysis Consortium (DPAC) ahead of the Gaia DR5 publication.

The successful candidate will contribute to the following work packages:

• DU434: Spectroscopic binaries (0.45 FTE)
• DU474: Spectral analysis of strong gravitational lens candidates (0.1 FTE)
• DU650: Determination of the radial velocities in composite spectra (0.1 FTE)
• DU831: Determination of the astrophysical parameters of quasars (0.35 FTE)

Position Details

• Starting Date: January 1, 2027
• Duration: 2 years (funded by a PRODEX grant for 2027–2028), with potential extension up to 2030 (4 years total).
• Location: University of Liège, Belgium.
• Application Deadline: September 10, 2026.

Key Responsibilities

• Maintain, develop, implement, and document algorithmic methods for determining the astrophysical parameters of sources observed by Gaia.
• Ensure full integration and compliance with DPAC development standards and pipeline requirements.
• Contribute to scientific validation and the writing of DPAC documentation and peer-reviewed scientific papers.

Required Qualifications & Skills

Software & Data Science:

• Strong experience in object-oriented programming, specifically in Java and Python.
• Familiarity with machine-learning techniques and big-data science infrastructure.
• Asset: Prior experience within the Gaia DPAC environment and familiarity with its strict development rules is highly appreciated.

Mathematical & Statistical Background:

• Solid grounding in Bayesian inference, numerical optimization, and linear algebra.
• Experience with cross-correlation techniques, non-uniform Fourier analysis, and TODCOR (or TODCOR-like) methods.

Astrophysics Domain Knowledge:

• Strong background in spectroscopy and/or spectro-photometry (preferably with Gaia instruments).
• Expertise in at least one (ideally several) of the following fields: binary stars, quasars, and strong gravitational lensing.

How to Apply

Interested candidates should submit their application as a single PDF file to g.rauw@uliege.be by September 10, 2026. The PDF must include:

1. A detailed Curriculum Vitae, including a full list of publications.
2. A Cover Letter detailing your motivation and relevant experience.
3. Optional: The contact information of two professional references.

For further information about this position, please contact g.rauw@uliege.be or ldelchambre@uliege.be.

Key References

• Delchambre et al., 2023, Gaia DR3. Apsis. III. Non-stellar content and source classification, A&A, 674, A31 (ADS)
• Gaia Collaboration et al., 2023, Gaia DR3. The extragalactic content, A&A, 674, A41 (ADS)
• Gaia Collaboration et al., 2024, Gaia FPR: A catalogue of sources around quasars to search for strongly lensed quasars, A&A, 685, A130 (ADS)
• Gosset et al., 2025, Gaia DR3: Spectroscopic binary-star orbital solutions: The SB1 processing chain, A&A, 693, A124 (ADS)
• Katz et al., 2025, Gaia DR3 high radial velocity stars: genuine fast-moving objects or outliers?, A&A, 704, A294 (ADS)