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From: Sterrewacht Colloquium Notifier noreply@strw.leidenuniv.nl Subject: Leiden Colloquium Notification Date: 2 June 2025 at 09:30:02 CEST

This weeks's PhDCol

Speaker: Christian Groeneveld ()

Title: ''Galaxy clusters in the decametre sky''

Many galaxy clusters exhibit bright diffuse radio emission that traces the underlying structure of the intracluster medium (ICM). Determining the properties and uncovering the origin of this diffuse emission are essential for understanding the fundamental physics of the plasma in galaxy clusters. In particular, observations of diffuse emission in galaxy clusters provide unique insights into magnetic fields permeating the ICM, the merger history, and the nature of the relativistic electron plasma resulting from ancient AGN outbursts. nDetecting diffuse radio plasma in a large sample of galaxy clusters requires deep, high-sensitivity observations with sufficient angular resolution to accurately subtract compact sources. This is now feasible thanks to the Low-Frequency Array (LOFAR). In particular, the low-band antenna (LBA) allows us to observe diffuse emission at ultra-low radio frequencies. In this presentation, we present novel calibration strategies that allow us to reduce LOFAR LBA data at unprecedented low frequencies (between 10-30 MHz), as well as LOFAR LBA data with international baselines.

Date: Monday 2025-06-02 Time: 13:15 Location: BE 0.18 Host: