Most of the Universe consists of dark energy and dark matter, which are hidden from our view. However, even most of the “ordinary matter”, made of standard-model particles, remains unseen and unexplored. In the course of structure formation, only a small fraction of the baryons turned into stars - most remain in the form of a hot, strongly ionised, low-density, X-ray emitting plasma. In the innermost parts of galaxies this plasma is often referred to as interstellar medium (ISM), at large radii, well beyond the stellar component, as circumgalactic medium (CGM), in groups of galaxies as intragroup medium (IGrM), in clusters of galaxies as intracluster medium (ICM), and in the filaments of the cosmic web as intergalactic medium (IGM) or warm-hot intergalactic medium (WHIM). Since the hot phases of all these media share crucial similarities, we will refer to them at all scales as hot atmospheres. They can be best probed by observations at soft X-ray energies, which require spaceborne observatories, or using ground based mm-observations using the Sunyaev-Zeldovitch (SZ) effect.
Studies of the role of the hot galactic atmospheres and accreting supermassive black holes in galaxy evolution. We use proprietary and public multi-wavelength, mostly X-ray and radio, data to study nearby early-type galaxies and test various predictions of the so-called “precipitation” and black hole feedback models, and compare our data with state of the art numerical simulations.
Determine the dynamics, thermodynamics, and the chemical composition of the hot plasma by using multi-wavelength X-ray, SZ, and radio observations. We use mostly X-ray observations of cluster outskirts and merging galaxy clusters and complement these data with SZ and radio observations. We also study mock X-ray observations of state-of the-art cosmological simulations with existing and planned high-resolution X-ray observatories. Our group is involved in the scientific preparations for the Athena mission.
Use of machine learning to study the evolution of galaxies, clusters of galaxies, and the large scale structure of the Universe. We are also looking forward to observations of the evolution of the earliest massive galaxies and their central black holes using the James Webb Space Telescope (JWST).
Among the most important breakthroughs of the past years is the detection of gravitational waves by the Laser Interferometer Gravitational-wave Observatory (LIGO) and Virgo. In particular, the recent detection of the short gamma-ray burst GRB170817A associated with the gravitational wave signal GW170817 and produced by a binary neutron star merger, marks a milestone in multi-messenger astrophysics and highlights the importance of the efforts to search for electromagnetic counterparts to gravitational wave sources with space-borne instruments. Modern space observatories monitoring GRBs grew into several hundred million Euro missions. However, miniaturization recently opened new opportunities to monitor and localize GRBs with CubeSats (nano-satellites), which are affordable also for small countries and universities. Our group is involved in the HERMES-SP project and the CAMELOT initiative, including two in-orbit demonstration missions, GRBAlpha and VZLUSAT-2.
GRBAlpha has been successfully operating in orbit since March 2021 and at time of writing has detected 5 gamma-ray bursts. VZLUSAT-2 was successfully launched in January 2022. Our research group is leading the data analysis and the scientific exploitation of the GRB detectors on these missions. The HERMES-SP mission is expected to be launched in 2023.
Our group also hopes to be a bridge between astrophysics and theoretical physics, exploring exotic phenomena such as the quantum structure of space and microscopic black-holes.