Coffee talks
Friday 24/11/2023 @ 11:30, Sala riunioni quarto piano e on-line (meet.google.com/sue-bwvk-axf)
Ariel Amaral (University of Toronto, Canada), "Towards Robust Interpretations of Magnetic Fields in AGN and Their Environments, and the Future of Large-scale RM-Grid Science"
In this presentation, I will discuss current and ongoing research focused on intensive broadband spectro-polarimetric data analysis of 49 classical double-lobed radio galaxies within the QUOCKA survey, specifically leveraging the June 2020 data release. Previous investigations into classical doubles have revealed intriguing property and depolarization asymmetries between lobes, such as the Laing-Garrington effect and the Liu-Pooley effect. These findings have spurred debates regarding the primary mechanisms behind observed depolarization in these sources—whether intrinsic to the source itself or induced by gas mixing and interactions with the surrounding environment (including the intra-cluster medium, IGM, or intra-group medium, IGrM). I will discuss QU-fitting modelling and RM-Synthesis techniques, implemented on the individual lobes of these sources, highlighting how the results provide crucial insights into the Rotation Measure (RM), the depolarization mechanisms (e.g., gas mixing), and intrinsic polarization properties. This approach facilitates a comprehensive understanding of the magnetic nature of these sources and their immediate surroundings. Moreover, I will emphasize the significance of employing extremely robust RMs, as exemplified in our AGN analysis, and utilizing these techniques to enhance our comprehension of the extragalactic source population. This, in turn, proves indispensable for upcoming large-scale RM-grid surveys (i.e. POSSUM, LOFAR, etc.), where studies using these data will contribute to the broader field of understanding extragalactic magnetism science—spanning scales from individual galaxies to clusters and filaments.