Radio Relics in Galaxy Clusters: the Curious Case of the Sausage Relic

Abstract: Radio relics are diffuse radio sources typically observed in merging galaxy cluster outskirts, tracing shock waves propagating in the intracluster medium. Shock waves are thought to be responsible for the (re-)acceleration of relativistic particles and for the amplification of the intracluster magnetic fields. These two elements interact through the synchrotron mechanism, giving rise to an arc-shaped polarized emission, with a spectral index gradient across the relic width.
In this talk, I will briefly review what we know about radio relics in galaxy clusters and present a recent study regarding the northern relic of CIZA J2242.8+5301. For the first time thanks to the capabilities of the Sardinia Radio Telescope it has been possible to detect a radio relic at high frequency, i.e. 19 GHz, both in total intensity and polarization.

Brief CV of Dr. Francesca Loi:

She graduated in Physics from the University of Cagliari in 2014. In the same year, she began her PhD under the supervision of Matteo Murgia and Federica Govoni on the topic “Magnetic fields in galaxy clusters in the SKA era” at INAF-Osservatorio Astronomico di Cagliari. After obtaining her PhD, she started her first Post Doc in 2018 at the University of Bologna in collaboration with Annalisa Bonafede. The project aimed to make predictions on the studies of magnetic fields in clusters with SKA through numerical simulations. Since the end of 2019, she has started her second Post Doc at INAF-Osservatorio Astronomico di Cagliari in collaboration with Paolo Serra, Federica Govoni, and Matteo Murgia to map the magnetic field of the Fornax galaxy cluster with data from the MeerKAT radio telescope.