![]() The observations of polarized radio emission from galaxy clusters were performed with this telescope at wavelengths of 3 and 6 cm. The 100-m radio telescope near Bad Münstereifel-Effelsberg. Such short wavelengths are advantageous because the polarized emission is not diminished when passing through the galaxy cluster and our Milky Way. They used the MPIfR's 100-m radio telescope near Bad Münstereifel-Effelsberg in the Eifel hills at wavelengths of 3 cm and 6 cm. This effect was detected in four galaxy clusters by a team of researchers at the Max Planck Institute for Radio Astronomy in Bonn (MPIfR), the Argelander Institute for Radio Astronomy at the University of Bonn (AIfA), the Thuringia State Observatory at Tautenburg (TLS), and colleagues in Cambridge/USA. More precisely, the emission becomes linearly polarized. The compression of magnetic fields orders the field lines, which also affects the emitted radio waves. ![]() Radio waves are excellent tracers of relics. They are messengers of huge gas flows that continuously shape the structure of the universe. Since their discovery in 1970 with a radio telescope near Cambridge/UK, relics were found in about 70 galaxy clusters so far, but many more are likely to exist. The resulting arc-like features are called "relics" and stand out by their radio and X-ray emission. Collision of galaxy clusters leads to a shock compression of the hot cluster gas and of the magnetic fields. 100 times the diameter of the Milky Way, they host a large number of such stellar systems, along with hot gas, magnetic fields, charged particles, embedded in large haloes of dark matter, the composition of which is unknown. With a typical extent of about 10 million light years, i.e. Galaxy clusters are the largest gravitationally bound structures in the universe. The results will be published on March 22 in the journal Astronomy & Astrophysics. This makes them the most extended magnetic fields in the universe known so far. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. Kierdorf et al., A&A 600, A18Īstronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. The bright source at the bottom is a radio galaxy that belongs to the same galaxy cluster. The short dashes indicate the orientation of the magnetic field. The colors represent the distribution of linearly polarized radio intensity at the chosen wavelength, in units of Milli-Jansky per telescope beam. The contour lines show the intensity of the radio emission at a wavelength of 3 cm, observed with the 100-m Effelsberg radio telescope. The relic at the outskirts of the galaxy cluster CIZA J2242+53, named „Sausage“ because of its shape, is located at a distance of about two billion light years from us.
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