A search for extended radio emission from selected compact galaxy groups
arXiv:1705.06210 · doi:10.1051/0004-6361/201630245
Abstract
Context. Studies on compact galaxy groups have led to the conclusion that a plenitude of phenomena take place in between galaxies that form them. However, radio data on these objects are extremely scarce and not much is known concerning the existence and role of the magnetic field in intergalactic space. Aims. We aim to study a small sample of galaxy groups that look promising as possible sources of intergalactic magnetic fields; for example data from radio surveys suggest that most of the radio emission is due to extended, diffuse structures in and out of the galaxies. Methods. We used the Effelsberg 100 m radio telescope at 4.85 GHz and NRAO VLA Sky Survey (NVSS) data at 1.40 GHz. After subtraction of compact sources we analysed the maps searching for diffuse, intergalactic radio emission. Spectral index and magnetic field properties were derived. Results. Intergalactic magnetic fields exist in groups HCG 15 and HCG 60, whereas there are no signs of them in HCG 68. There are also hints of an intergalactic bridge in HCG 44 at 4.85 GHz. Conclusions. Intergalactic magnetic fields exist in galaxy groups and their energy density may be comparable to the thermal (X-ray) density, suggesting an important role of the magnetic field in the intra-group medium, wherever it is detected.
arXiv comment13 pages, 4 figures, 3 tables, accepted for publication in A&A
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Cited by in corpus (6)
- Diffuse Radio Emission from Galaxy Clusters
- Diffuse Radio Emission from Galaxy Clusters in the LOFAR Two-metre Sky Survey Deep Fields
- Exploring the properties of low-frequency radio emission and magnetic fields in a sample of compact galaxy groups using the LOFAR Two-Metre Sky Survey (LoTSS)
- Revealing A Head-on Major Merger in the Nearby NGC 6338 Group with Chandra and VLA observations
- Somewhere in between: Tracing the Radio Emission from Galaxy Groups (or Why Does the Future of Observing Galaxy Groups with Radio Telescopes Look Promising?)
- Relighting the fire in Hickson Compact Group (HCG) 15: magnetised fossil plasma revealed by the SKA Pathfinders & Precursors