Coffee talks
Friday 14/05/2021 @ 11:30, On-line - meet.google.com/sue-bwvk-axf
Francesca Loi (OAC-INAF), "What we can learn about radio relic with 19 GHz SRT observations: the example of the sausage radio relic"
Observations of radio relics at very high frequency (>10 GHz) can help to understand how particles age and are (re-)accelerated in galaxy cluster outskirts and how magnetic fields are amplified in these environments. In this talk, I will present the result of an observation campaing of the well-known northern radio relic of CIZA J2242.8+5301 conducted at 18.6 GHz with the Sardinia Radio Telescope and at 14.25 GHz with the Effelsberg telescope. At variance with previous studies, we found that the best-fitting model of the relic spectrum from 145 MHz to 18.6 GHz is a power-law spectrum with spectral index ? = 1.12 ± 0.03: no evidence of steepening has been found in the new data presented in this work. Moreover, for the first time, polarization properties have been derived at 18.6 GHz, revealing an averaged polarization fraction of ? 40% and a magnetic field aligned with the ’filaments’ or ’sheets’ of the relic.