Search for Positronium Recombination Lines with the Effelsberg 100m Radio Telescope

Positronium (Ps) is an intermediate bound state of an electron and a positron. The annihilation of Ps has been measured with gamma-ray telescopes, suggesting charge exchange with interstellar gas. Similar to hydrogen, Ps is not formed in the ground state but in excited states, which leads to atomic transitions, so called recombination lines. At the chair for astronomy, we are running the key science program ‘TELAMON’ on the Effelsberg 100m radio telescope since 2020 and have accumulated more than 1700 hours of data. Within the frequency bands of TELAMON, more than 20 Ps recombination lines are predicted by theory. In previous shallower observations, Ps recombination has never been detected due to limited sensitivity. In this interdisciplinary Bachelor thesis, the superior TELAMON data will be analysed for residual signals of Ps recombination lines by applying novel techniques in collaboration with the chair for machine learning in complex systems at the Center for Artificial Intelligence and Data Science (CAIDAS).

More information:

TELAMON program website:

Recent Publications: 

Contact persons:

Dr. Thomas Siegert:

Prof. Dr. Matthias Kadler: