During this talk I intend to present radio observations with the Sardinia Radio Telescope (SRT) of a region of the sky of 8°x8°, likely associated with an over-density traced by nine massive galaxy clusters at z≈0.1. The combination of the SRT data with observations from the NRAO VLA Sky Survey revealed the presence of 28 new diffuse synchrotron radio sources with radio emissivity and X-ray luminosity 10-100 fainter than known diffuse synchrotron cluster sources (radio halos and relics). The comparison with magneto-hydro-dynamical simulations suggests that this population is potentially the tip of the iceberg of a class of diffuse large-scale synchroton sources associated with the filaments of the cosmic web and corresponding to magnetic field strengths of ~20-50 nG.

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Oggi Astro Chiacchiere! è un incontro informale tra il personale dell'Osservatorio Astronomico di Cagliari (staff, postdoc e studenti), che ha lo scopo di discutere argomenti di carattere prevalentemente scientifico, tecnologico, informativo sulle attività dell'Osservatorio.  L'incontro si tiene solitamente il Martedì, alle ore 11:30, nell'Auditorium dell'Osservatorio Astronomico di Cagliari. Per informazioni e/o contributi contattare vvacca@oa-cagliari.inaf.it e surcis@oa-cagliari.inaf.it