Servicenavigation

Project Details

Back

Projekt Print View

PRODIGIES: Polarised Radio Observations of DIGItal Extragalactic Shocks

Applicant Professor Marcus Brüggen, Ph.D., since 1/2023
Subject Area Astrophysics and Astronomy
Term from 2020 to 2023
Project identifier Deutsche Forschungsgemeinschaft (DFG) - Project number 441694982
 
Final Report Year 2024

Final Report Abstract

The project’s goal was to study the physics of Radio Relics, to gain a better understanding of the magnetic fields and shock acceleration processes in galaxy clusters. Radio Relics are arc-shaped diffuse synchrotron sources that reside in the outskirts of galaxy clusters. Radio Relics illuminate the large-scale magnetic fields and cosmic-ray electrons in the intracluster medium (ICM) – the hot and ionized plasma inside galaxy clusters. It is commonly accepted that shocks in the ICM accelerate the cosmic-ray electrons to the required energies. However, the details of the shock acceleration mechanism as well as the physics of the large-scale magnetic fields are not yet fully understood. The new generation of radio telescopes has provided a wealth of high-resolution observations that show Radio Relics with an unprecedented detailed view. However, to connect these observations to the underlying theoretical models, numerical simulations are unambigously. This project targeted to fill the previously present lack of such simulations. The main goal of the project was to provide high resolution cosmological simulations of Radio Relics to gain new insights on their origin. A special emphasize was put on the Radio Relics’ polarized emission. The polarized emission contains information on the local magnetic field topology, that plays a crucial role in the acceleration process. Within this project, we produced to the most detailed cosmological simulations of Radio Relics to-date. With these simulations, we answered several questions about Radio Relics. We explained the Mach number discrepancy – a discrepancy between X-ray and radio observations that measure the strength of the Radio Relic producing shock wave. We found that the two measurements are intrinsically different, as they access different parts of the shock wave’s Mach number distribution. Moreover, we studied the observed filamentary substructures of Radio Relics, finding that Radio Relics consist of 3D filaments. Finally, our simulations were used to help the interpretation of the Radio Relics observed in Abell 523, Abell 2256, Abell 2477, Abell 3667, CIZA J2242.8+5301, and MACS J0717.5+3745. Additionally, we studied the role of Active Galactic Nuclei (AGN), that could provide the seed electrons for Radio Relics. In a first series of works, we studied the turbulent motion induced by AGN into the ICM. Here, we found that stretching motions and rarefractions are the dominant sources and sinks of turbulent motions. In a second series of works, we studied how AGN transport cosmic-ray electrons into the sourrounding ICM. Finally, we have investigated the shock acceleration mechanism beyond galaxy clusters. In total, this project contributed to 28 scientific publications.

Publications

 
 

Additional Information

© 2025 DFG Disclaimer / Copyright / Privacy Policy

Textvergrößerung und Kontrastanpassung