New high-frequency radio observations of Cygnus Loop SNR

Cygnus Loop is one of the most well-studied middle-aged Supernova Remnants (SNRs). If on one hand its large size (∼ 4◦×3◦) makes this SNR particularly well-suited for morphological studies across the entire accessible electro-magnetic spectrum, on the other it involves technical difficulties on the radio observations and related flux density measurements, which are available in literature only up to ∼ 5 GHz. With the aim to study the complex morphology of the Cygnus Loop with detailed continuum radio maps at higher frequencies than those available so far, we observed the whole SNR at 8.5 GHz with the Medicina Radio Telescope and the northern-bright filament at 7.0 and 18.7 GHz with the Sardinia Radio Telescope. We studied the integrated spectrum of Cygnus Loop by using our flux density measurement at 8.5 GHz with those available in literature, and we modelled it with a simple synchrotron power-law function. Our measurement rules out any spectral steepening up to high radio frequencies, and it confirms the trend suggested by the Planck data at 30 GHz. We coupled the preliminary measurements related to the northern filament at 7.0, 8.5 and 18.7 GHz in order to study its integrated spectrum. Our data suggest a spectral steepening between around 10 and 20 GHz associated with this peculiar region.