Studying the Hot Universe
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.
Ongoing research projects in the group include:
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).
Studying the Energetic Universe
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, to be launched in the first half of 2021.
Our goal is to demonstrate that monitoring and timing based localization of gamma-ray bursts, some of which are the electromagnetic counterparts of gravitational wave events, can be performed using CubeSats. Together with our international collaborators (Konkoly Observatory, INAF, ELTE, VZLU), we are helping to develop CubeSat missions that are able to perform breakthrough science in the field of High-Energy Astrophysics.
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.
Integrated Activities for the High Energy Astrophysics Domain (AHEAD2020)
AHEAD2020 builds on our previous program, funded in H2020 as starting community, that allowed us to qualify now as advanced community. Our overall objective remains to advance further the integration of national efforts in high-energy astrophysics keeping the community at the cutting edge of science and technology and ensuring that observatories are at the state of the art. At the same time, AHEAD2020 aims at widening its horizons to further integrate activities with the newly born multimessenger astronomy, boosted very recently by the discovery of gravitational waves and cosmic neutrinos and of their first high energy counterparts. This will be achieved by a new large community of high energy astronomers, gravitational wave and astroparticle scientists. Along the road paved until recently, we will keep strengthening the theorethical efforts, also building up on the results of the observations of multimessenger sources; and continue opening the best infrastructures for data analysis of high-energy space and ground observatories. Furthermore we will integrate key infrastructures for on-ground test and calibration of spacebased instrumentation and promote their coordinated use. Technological developments will focus on the improvement of selected detector, optics devices and advanced analysis tools for the benefit of future space missions and groundbased multimessenger facilities, with more emphasis on the observation of the new transient Universe.
