Beyond stars and galaxies, the Universe is teeming with even more mysterious objects. A common characteristics is that they have extreme physical properties. Neutron stars and stellar-mass black holes are extraordinarily dense objects, whose gravitational fields tear apart space-time itself. Black holes millions to billions of times the mass of the Sun lurk in the center of all galaxies, possibly affecting the history of star formation Clusters of galaxies are the most massive gravitationally bound structures in the Universe and are filled with hot plasma that can reach 100 millions of degrees. Elementary particles can be accelerated up to ultra-relativistic energies in the vicinity of supermassive black holes, pulsars, or even some very massive stars. Most of the matter in the Universe itself is in a form that is yet unknown, while its energy content is dominated by some form of energy that is even more mysterious. These phenomena often result in the emission of high-energy electromagnetic radiation in the X-ray and gamma-ray bands.

The activities of the Extreme Universe group of the Department of Astronomy focus on the study of these extreme phenomena across the electromagnetic spectrum, where X-ray and gamma-ray observation play a particularly significant role. and via different messengers, like cosmic rays and gravitational waves. 

This research is at the forefront of data science and big data, with huge and complex data sets and a generalized usage of deep-learning-based methods. Numerical simulations play an important role in our research activities.

The different groups are strongly involved in large observational projects, with significant contributions to the development of the Euclid, UVEX, and NewAthena missions, as well as to that of the THESEUS mission, which is still under selection.