Deep Very Large Array Observations of the Merging Cluster CIZA J2242.8+5301: Continuum and Spectral Imaging
Despite the progress that has been made in understanding radio relics, there are still open questions regarding the underlying particle acceleration mechanisms. In this paper, we present deep 1-4 GHz Very Large Array (VLA) observations of CIZA J2242.8+5301 (z = 0.1921), a double radio relic cluster...
| Main Authors: | , , , , , , , , , , , , , , , , |
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| Format: | Journal Article |
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Institute of Physics Publishing
2018
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| Online Access: | http://hdl.handle.net/20.500.11937/74510 |
| _version_ | 1848763295311331328 |
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| author | Gennaro, G. Van Weeren, R. Hoeft, M. Kang, H. Ryu, D. Rudnick, L. Forman, W. Röttgering, H. Brüggen, M. Dawson, W. Golovich, N. Hoang, D. Intema, Hubertus Jones, C. Kraft, R. Shimwell, T. Stroe, A. |
| author_facet | Gennaro, G. Van Weeren, R. Hoeft, M. Kang, H. Ryu, D. Rudnick, L. Forman, W. Röttgering, H. Brüggen, M. Dawson, W. Golovich, N. Hoang, D. Intema, Hubertus Jones, C. Kraft, R. Shimwell, T. Stroe, A. |
| author_sort | Gennaro, G. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Despite the progress that has been made in understanding radio relics, there are still open questions regarding the underlying particle acceleration mechanisms. In this paper, we present deep 1-4 GHz Very Large Array (VLA) observations of CIZA J2242.8+5301 (z = 0.1921), a double radio relic cluster characterized by small projection on the plane of the sky. Our VLA observations reveal, for the first time, the complex morphology of the diffuse sources and the filamentary structure of the northern relic. We discover new, faint, diffuse radio emission extending north of the main northern relic. Our Mach number estimates for the northern and southern relics, based on the radio spectral index map obtained using the VLA observations and existing LOw Frequency ARray (LOFAR) and Giant Metrewave Radio Telescope data, are consistent with previous radio and X-ray studies (MRN = 2.58 ± 0.17 and MRS = 2.10 ± 0.08). However, color-color diagrams and models suggest a flatter injection spectral index than the one obtained from the spectral index map, indicating that projection effects might be not entirely negligible. The southern relic consists of five "arms." Embedded in it, we find a tailed radio galaxy that seems to be connected to the relic. A spectral index flattening, where the radio tail connects to the relic, is also measured. We propose that the southern relic may trace AGN fossil electrons that are reaccelerated by a shock, with an estimated strength of M = 2.4. High-resolution mapping of other tailed radio galaxies also supports a scenario where AGN fossil electrons are revived by the merger event and could be related to the formation of some diffuse cluster radio emission. |
| first_indexed | 2025-11-14T11:01:11Z |
| format | Journal Article |
| id | curtin-20.500.11937-74510 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T11:01:11Z |
| publishDate | 2018 |
| publisher | Institute of Physics Publishing |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-745102019-10-04T02:57:00Z Deep Very Large Array Observations of the Merging Cluster CIZA J2242.8+5301: Continuum and Spectral Imaging Gennaro, G. Van Weeren, R. Hoeft, M. Kang, H. Ryu, D. Rudnick, L. Forman, W. Röttgering, H. Brüggen, M. Dawson, W. Golovich, N. Hoang, D. Intema, Hubertus Jones, C. Kraft, R. Shimwell, T. Stroe, A. Despite the progress that has been made in understanding radio relics, there are still open questions regarding the underlying particle acceleration mechanisms. In this paper, we present deep 1-4 GHz Very Large Array (VLA) observations of CIZA J2242.8+5301 (z = 0.1921), a double radio relic cluster characterized by small projection on the plane of the sky. Our VLA observations reveal, for the first time, the complex morphology of the diffuse sources and the filamentary structure of the northern relic. We discover new, faint, diffuse radio emission extending north of the main northern relic. Our Mach number estimates for the northern and southern relics, based on the radio spectral index map obtained using the VLA observations and existing LOw Frequency ARray (LOFAR) and Giant Metrewave Radio Telescope data, are consistent with previous radio and X-ray studies (MRN = 2.58 ± 0.17 and MRS = 2.10 ± 0.08). However, color-color diagrams and models suggest a flatter injection spectral index than the one obtained from the spectral index map, indicating that projection effects might be not entirely negligible. The southern relic consists of five "arms." Embedded in it, we find a tailed radio galaxy that seems to be connected to the relic. A spectral index flattening, where the radio tail connects to the relic, is also measured. We propose that the southern relic may trace AGN fossil electrons that are reaccelerated by a shock, with an estimated strength of M = 2.4. High-resolution mapping of other tailed radio galaxies also supports a scenario where AGN fossil electrons are revived by the merger event and could be related to the formation of some diffuse cluster radio emission. 2018 Journal Article http://hdl.handle.net/20.500.11937/74510 10.3847/1538-4357/aad738 Institute of Physics Publishing fulltext |
| spellingShingle | Gennaro, G. Van Weeren, R. Hoeft, M. Kang, H. Ryu, D. Rudnick, L. Forman, W. Röttgering, H. Brüggen, M. Dawson, W. Golovich, N. Hoang, D. Intema, Hubertus Jones, C. Kraft, R. Shimwell, T. Stroe, A. Deep Very Large Array Observations of the Merging Cluster CIZA J2242.8+5301: Continuum and Spectral Imaging |
| title | Deep Very Large Array Observations of the Merging Cluster CIZA J2242.8+5301: Continuum and Spectral Imaging |
| title_full | Deep Very Large Array Observations of the Merging Cluster CIZA J2242.8+5301: Continuum and Spectral Imaging |
| title_fullStr | Deep Very Large Array Observations of the Merging Cluster CIZA J2242.8+5301: Continuum and Spectral Imaging |
| title_full_unstemmed | Deep Very Large Array Observations of the Merging Cluster CIZA J2242.8+5301: Continuum and Spectral Imaging |
| title_short | Deep Very Large Array Observations of the Merging Cluster CIZA J2242.8+5301: Continuum and Spectral Imaging |
| title_sort | deep very large array observations of the merging cluster ciza j2242.8+5301: continuum and spectral imaging |
| url | http://hdl.handle.net/20.500.11937/74510 |