FOR 5195:  Relativistic Jets in Active Galaxies

• Subject Area: Physics
• Term: since 2021
• Website: Homepage
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 443220636

Active Galactic Nuclei (AGN) can form powerful collimated relativistic outflows, called jets, which carry a fraction of the total gravitational energy released during the accretion of matter onto a supermassive black hole (SMBH) at the centre of the AGN. AGN jets emit brightly across the electromagnetic spectrum, often exhibit apparent superluminal motion, and are involved in the regulation of star formation and galaxy evolution via AGN feedback in the interstellar medium (ISM). Beyond the galaxy scale, AGN jets play a dominant role in heating the intracluster medium (ICM) and cause a substantial impact on the evolution of galaxy clusters and cosmological structure formation. The formation of jets addresses long-standing fundamental questions related to the extraction of rotational energy from the central SMBH and the formation of hydromagnetic flows from accretion disks around such compact objects. Imaging of AGN jets is now possible in the radio band using Very Long Baseline Interferometry (VLBI) at millimetre wavelengths, yielding unprecedented angular resolution of the jet-launching zone and how this is embedded in the SMBH neighbourhood. It is now clear that AGN jets are emerging from SMBHs with foot points as small as a few gravitational radii, and very-high-energy γ-ray observations have demonstrated the existence of emission regions even smaller than one gravitational radius. Recently, AGN jets have been associated with very-high-energy neutrinos and are among the most likely candidates for the long sought-after sources of ultrahigh-energy cosmic rays. These impressive observational breakthroughs within only a few years have moved AGN jets into the focus of modern astroparticle physics. However, fundamental questions on their role and physics are still open: 1. How are relativistic jets launched from the vicinity of supermassive black holes? How are they accelerated and collimated? 2. Which radiative and dynamic processes govern the high-energy emission of AGN jets and what are AGN jets composed of? 3. How do AGN jets interact with their environment in galaxy groups and clusters across cosmic time and which processes determine their morphological appearance? How does AGN feedback heat the ICM and which are the observational signatures? This research unit brings together world-leading experts on theory, modeling, observation, and interpretation of all relevant angles of AGN-jet physics to deliver answers to these questions in the light of game-changing new observational information collected by the latest astronomical facilities at all observational wavelengths and inferred from state-of-the-art simulations from event-horizon scales to cosmological gigaparsec scales.

• DFG Programme: Research Units
• International Connection: Greece, India, Spain, United Kingdom, USA

Projects

• Coordination Funds (Applicant Kadler, Matthias )
• Flaring and Time-Dependent Modeling of Blazars (Applicant Wagner, Stefan )
• Jet Composition under Scrutiny (Applicants Fendt, Christian ;  Mannheim, Ph.D., Karl )
• Jet Feedback on Groups and Galaxy Clusters (Applicants Brüggen, Ph.D., Marcus ;  Pfrommer, Christoph )
• Jet Lamp-Post Models for Radio-Loud AGN (Applicant Wilms, Jörn )
• Jet Lamp-Post Models for Radio-Loud AGN (Applicant Dauser, Thomas )
• Jet Physics Across the Multimessenger Spectrum (Applicant Buson, Ph.D., Sara )
• Jet Physics on Event Horizon Scales and Beyond (Applicants Fromm, Christian ;  Ros, Ph.D., Eduardo )
• Large-Scale Blazar Jets: Clues on High-Energy Emission from Low-Frequency Radio Observations (Applicant Kadler, Matthias )
• mm-VLBI Studies of Gamma-Ray Bright Radio Galaxies (Applicant Zensus, J. Anton )
• Short-Wavelength Radio Variability of High-Energy Emitting AGN Jets (Applicant Kadler, Matthias )
• Supermassive black holes and their jets through cosmic time (Applicant Marcotulli, Ph.D., Lea )

• Spokesperson: Professor Dr. Matthias Kadler