First evidence of diffuse ultra-steep-spectrum radio emission surrounding the cool core of a cluster
Diffuse synchrotron radio emission from cosmic ray electrons is observed at the centre of a number of galaxy clusters. These sources can be classified either as giant radio haloes, which occur in merging clusters, or as mini haloes, which are found only in cool-core clusters. In this paper, we prese...
| Main Authors: | , , , , , , , , , , , , , , , , |
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| Format: | Journal Article |
| Published: |
Oxford University Press
2018
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| Online Access: | http://hdl.handle.net/20.500.11937/74037 |
| _version_ | 1848763163478065152 |
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| author | Savini, F. Bonafede, A. Brüggen, M. van Weeren, R. Brunetti, G. Intema, Hubertus Botteon, A. Shimwell, T. Wilber, A. Rafferty, D. Giacintucci, S. Cassano, R. Cuciti, V. de Gasperin, F. Röttgering, H. Hoeft, M. White, G. |
| author_facet | Savini, F. Bonafede, A. Brüggen, M. van Weeren, R. Brunetti, G. Intema, Hubertus Botteon, A. Shimwell, T. Wilber, A. Rafferty, D. Giacintucci, S. Cassano, R. Cuciti, V. de Gasperin, F. Röttgering, H. Hoeft, M. White, G. |
| author_sort | Savini, F. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Diffuse synchrotron radio emission from cosmic ray electrons is observed at the centre of a number of galaxy clusters. These sources can be classified either as giant radio haloes, which occur in merging clusters, or as mini haloes, which are found only in cool-core clusters. In this paper, we present the first discovery of a cool-core cluster with an associated mini halo that also shows ultra-steep-spectrum emission extending well beyond the core that resembles radio halo emission. The large-scale component is discovered thanks to LOFAR observations at 144 MHz. We also analyse GMRT observations at 610 MHz to characterize the spectrum of the radio emission. An X-ray analysis reveals that the cluster is slightly disturbed, and we suggest that the steep-spectrum radio emission outside the core could be produced by a minor merger that powers electron re-acceleration without disrupting the cool core. This discovery suggests that, under particular circumstances, both a mini halo and giant halo could co-exist in a single cluster, opening new perspectives for particle acceleration mechanisms in galaxy clusters. |
| first_indexed | 2025-11-14T10:59:06Z |
| format | Journal Article |
| id | curtin-20.500.11937-74037 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:59:06Z |
| publishDate | 2018 |
| publisher | Oxford University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-740372019-03-13T03:33:01Z First evidence of diffuse ultra-steep-spectrum radio emission surrounding the cool core of a cluster Savini, F. Bonafede, A. Brüggen, M. van Weeren, R. Brunetti, G. Intema, Hubertus Botteon, A. Shimwell, T. Wilber, A. Rafferty, D. Giacintucci, S. Cassano, R. Cuciti, V. de Gasperin, F. Röttgering, H. Hoeft, M. White, G. Diffuse synchrotron radio emission from cosmic ray electrons is observed at the centre of a number of galaxy clusters. These sources can be classified either as giant radio haloes, which occur in merging clusters, or as mini haloes, which are found only in cool-core clusters. In this paper, we present the first discovery of a cool-core cluster with an associated mini halo that also shows ultra-steep-spectrum emission extending well beyond the core that resembles radio halo emission. The large-scale component is discovered thanks to LOFAR observations at 144 MHz. We also analyse GMRT observations at 610 MHz to characterize the spectrum of the radio emission. An X-ray analysis reveals that the cluster is slightly disturbed, and we suggest that the steep-spectrum radio emission outside the core could be produced by a minor merger that powers electron re-acceleration without disrupting the cool core. This discovery suggests that, under particular circumstances, both a mini halo and giant halo could co-exist in a single cluster, opening new perspectives for particle acceleration mechanisms in galaxy clusters. 2018 Journal Article http://hdl.handle.net/20.500.11937/74037 10.1093/MNRAS/STY1125 Oxford University Press fulltext |
| spellingShingle | Savini, F. Bonafede, A. Brüggen, M. van Weeren, R. Brunetti, G. Intema, Hubertus Botteon, A. Shimwell, T. Wilber, A. Rafferty, D. Giacintucci, S. Cassano, R. Cuciti, V. de Gasperin, F. Röttgering, H. Hoeft, M. White, G. First evidence of diffuse ultra-steep-spectrum radio emission surrounding the cool core of a cluster |
| title | First evidence of diffuse ultra-steep-spectrum radio emission surrounding the cool core of a cluster |
| title_full | First evidence of diffuse ultra-steep-spectrum radio emission surrounding the cool core of a cluster |
| title_fullStr | First evidence of diffuse ultra-steep-spectrum radio emission surrounding the cool core of a cluster |
| title_full_unstemmed | First evidence of diffuse ultra-steep-spectrum radio emission surrounding the cool core of a cluster |
| title_short | First evidence of diffuse ultra-steep-spectrum radio emission surrounding the cool core of a cluster |
| title_sort | first evidence of diffuse ultra-steep-spectrum radio emission surrounding the cool core of a cluster |
| url | http://hdl.handle.net/20.500.11937/74037 |