Postdoctoral Fellow-Pyxel detector simulation for WST

For its Office for Science within the Directorate for Science at its headquarters in Garching, Germany, ESO is offering the position of Postdoctoral Fellow – Pyxel detector simulation for WST.

The Wide-field Spectroscopic Telescope (WST: arXiv: , is an innovative 12‑m class wide‑field spectroscopic telescope with simultaneous operation of a large field‑of‑view (3 square degrees) and high multiplex (30,000) multi‑object spectrograph facility with both medium and high resolution modes (MOS), and a giant panoramic (3×3 square arcminutes) integral field spectrograph (IFS).

WST is a Research and Innovation Action funded by the European Research Executive Agency (REA) under the powers delegated by the European Commission under Grant Agreement No. – WST – HORIZON-INFRA‑2024‑DEV‑01.

Under this agreement, ESO is contributing, among other, to the WST Detector Workpackage. Within this framework ESO is offering a postdoctoral research position for the development of detector simulations using the Pyxel environment (

For WST, the detector is one of the drivers of system performance, and a full detector trade‑off is currently ongoing (CCD vs CMOS, silicon thickness and QE, operating temperature). The goal of this project is to produce high‑fidelity simulations of the actual detector readouts of the instrument’s focal plane, thereby extending the instrument’s end‑to‑end simulation to also include the impact of detector effects on scientific data. These simulations will directly support the WST detector trade‑off by quantifying the impact of detector physics on the survey performance. The simulations may be extended to detectors currently under test at ESO for future instrumentation.

The simulations will be conducted using the Pyxel detector simulation framework: which is written in Python. This framework is developed and supported by ESA and ESO is a contributor for detector models and functions with inputs from the ESO detector group.

Main Duties and Responsibilities

• Closely interacting with the detector engineers of the ESO detector group to understand which detectors and effects are the most important for science to be included in the simulations, specifically for WST, where we need to analyse and evaluate the impact of the glow, charge diffusion vs thickness, pixel response and other architecture dependencies;
• Coding in Python to implement said models and convenience functions to fabricate ‘Toy models’ of the detectors. These can be integrated into the end‑to‑end simulations for preliminary studies of detector performance and/or trade‑off or on the science impact that some detector effects would have. For WST, these models will allow comparison of candidates, technologies and operating conditions;
• Participating in the detector characterisation test campaign with members of ESO’s detector group, with suggestions of datasets to be acquired for the Pyxel model validation. This includes collecting datasets explicitly selected to validate WST‑specific detector effects (e.g. glow, PRNU, diffusion tails, QE vs. thickness);
• Regular meetings with the ESA Pyxel developers and with the instrument’s simulator teams.
• The successful candidate should be comfortable in working with Python. Python support will be available from the ESO detector group.

The above responsibilities are not exhaustive and a flexible approach and willingness to adapt to operational needs are required.

Key Competences and Experience

Essential Competences and Experience

• Experience in object‑oriented and scientific programming in Python (e.g. NumPy, SciPy or similar);
• Ability to develop physical model based on experimental data;
• Knowledge of CMOS detector technologies;
• Understanding of the impact of detector characteristics on the scientific performance of astronomical instruments;
• Ability to work in the context of interdisciplinary and international collaborations.

Desirable Competences and Experience

• Experience in detector physics;
• Knowledge of CCD detector principles and technology;
• Experience with experimental detector characterization setups;
• Familiarity with version control systems (e.g. Git).

Qualifications

Applicants must hold a PhD in disciplines such as engineering, physics, astronomy or a related discipline by 1 October 2026.

Language skills

The position requires an excellent command of English, both written and spoken.

Remuneration and Contract

We offer an attractive remuneration package including a competitive salary and allowances, comprehensive social benefits, and we provide financial support for relocating families. Salary will be in line with ESO Fellow salaries. The position includes the benefits as outlined under Fellows ESO ( however, the duration of the contract is limited to one year. The position may be extended based on performance and availability of another source of funding.

Duty Station

The role is based on‑site at ESO’s Headquarters in Garching near Munich, Germany and relocation to this duty station area is required. Staff at ESO benefit from a mobile working policy that allows for limited hybrid working for work‑life balance purposes.

ESO Values

An important element in any successful employment relationship is harmony in values between an organisation and its people.

• ESO strives for excellence through innovation .
• ESO provides outstanding services to its communities .
• ESO fosters diversity & inclusion .
• ESO believes in the key role of sustainability for its future.

Achieving the above are recognized as only possible on the basis of personal values and attitudes that we expect from our employees: respect, integrity, accountability, commitment, collaboration, and clear & open communication .

Applicants to any ESO role are asked to reflect on their affinity with these values and advised they may be asked about them if called for interview.

Diversity

ESO has established diversity as an important value of the Organisation, is committed to providing an equal opportunities environment and is actively seeking to promote a diverse, equitable and inclusive workforce. Please visit for further details.

Nationality

No nationality is in principle excluded from employment at ESO, however, recruitment preference will be given to nationals of our Member States, host states and strategic partners: Australia, Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland, the United Kingdom and Chile, irrespective of gender, age, disability, sexual orientation, ethnicity or religion.