28.01.2026

Erfolgreiche Verteidigung at IAAT von Herrn Marvin Neumann

On 21 February, Mr. Marvin Neumann successfully defended his PhD thesis at the Institute of Astronomy and Astrophysics Tübingen (IAAT).
His doctoral research comprises two projects in X-ray astronomy, focusing on source population studies and advanced data analysis methods.
The first project investigates X-ray binaries, systems in which a neutron star or black hole accretes matter from a non-degenerate companion star. Depending on the companion’s mass, these systems are classified as Low-Mass or High-Mass X-ray Binaries (LMXBs and HMXBs). As some of the most luminous X-ray sources in the Universe, they are observed both within and beyond the Milky Way. While the most recent comprehensive catalogues of Galactic LMXBs and HMXBs date back to 2003–2007, numerous new systems have since been discovered and key source parameters have been revised. To address this, the thesis presents two updated catalogues of Galactic LMXBs and HMXBs, providing an essential resource for population studies. An accompanying website enables interactive exploration of both source classes.

The second project addresses background reduction in XMM-Newton observations. Standard background subtraction can produce unphysical negative source counts at low count rates, while model-based approaches require substantial computational effort and prior source knowledge. To overcome these limitations, a novel probabilistic method was developed that avoids negative counts and does not rely on prior information about the source. Background estimation is based on stacked images created within the project, and the method was validated using both simulated data and real XMM-Newton observations.

Marvin Neumann completed his Bachelor’s, Master’s, and PhD studies in the High Energy Section of the IAAT and has therefore been a key contributor to the Institute. We wish Dr. Marvin Neumann all the best for his future career and personal life.

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