We study the high-energy Universe in gamma-rays. To measure these gamma-rays, we are involved in the most sensitive array of imaging atmospheric Cherenkov telescopes to date, the High Energy Stereoscopic System H.E.S.S. and the planning of the next generation instrument, the Cherenkov Telescope Array CTA.
The H.E.S.S. data allow the study of the key questions of cosmic rays: what are their sources and how do they propagate? In almost two decades of H.E.S.S. observations we have observed a multitude of Galactic and extragalactic gamma-ray sources (pulsar wind nebulae, supernova remnants, binary systems, blazars, just to name a few) and also diffuse gamma-ray emission in the Milky Way. Our group in Potsdam is active in the analysis and modelling of gamma-ray sources and diffuse emission. The low energy threshold and large sensitivity of H.E.S.S. II allows the study of phenomena on small time scales. Therefore, we also search for transient phenomena like gamma-ray bursts, which have just recently been observed for the first time ground based by the MAGIC and H.E.S.S. telescopes, and we are actively involved in the search for electromagnetic counterparts of gravitational wave events.
The H.E.S.S. experiment constantly works on the improvement and expansion of its functionality. In Potsdam, we have developed the H.E.S.S. automated alarm system for transient follow-up observations. This system connects H.E.S.S. with many experiments world-wide and allow automised reactions to alerts by repointing of the instrument within seconds. We are also engaged in the development of advanced photon reconstruction using deep learning techniques.
Hardware developments are conducted at our partner group at DESY Zeuthen. There, the upgrade of the four H.E.S.S. I cameras is currently ongoing.
For information on Bachelor, Master, and Ph.D. theses, see here.
Preparations are underway for a next generation observatory with dramatically improved performance. The Cherenkov Telescope Array (CTA) will consist of two arrays, one in each hemisphere, with around 100 telescopes of three different sizes. CTA will bring much better resolution, higher sensitivity, a much wider energy range, and a collection area of many square kilometres at the highest energies. Our group in Potsdam implements the alert system for CTA, which will allow CTA to follow up on a multitude of different triggers from various wavelengths and messengers to study e.g. gamma ray bursts, flaring active galactic nuclei, or the sources of astrophysical neutrinos or gravitational waves.