LOFAR, VLA, and Chandra Observations of the Toothbrush Galaxy Cluster
We present deep LOFAR observations between 120 and 181 MHz of the "Toothbrush" (RX J0603.3+4214), a cluster that contains one of the brightest radio relic sources known. Our LOFAR observations exploit a new and novel calibration scheme to probe 10 times deeper than any previous study in th...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Journal Article |
| Published: |
Institute of Physics Publishing
2016
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| Online Access: | http://hdl.handle.net/20.500.11937/74391 |
| _version_ | 1848763261569204224 |
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| author | Van Weeren, R. Brunetti, G. Brüggen, M. Andrade-Santos, F. Ogrean, G. Williams, W. Röttgering, H. Dawson, W. Forman, W. Gasperin, F. Hardcastle, M. Jones, C. Miley, G. Rafferty, D. Rudnick, L. Sabater, J. Sarazin, C. Shimwell, T. Bonafede, A. Best, P. Birzan, L. Cassano, R. Chyzy, K. Croston, J. Dijkema, T. Enßlin, T. Ferrari, C. Heald, G. Hoeft, M. Horellou, C. Jarvis, M. Kraft, R. Mevius, M. Intema, Hubertus Murray, S. Orrú, E. Pizzo, R. Sridhar, S. Simionescu, A. Stroe, A. Tol, S. White, G. |
| author_facet | Van Weeren, R. Brunetti, G. Brüggen, M. Andrade-Santos, F. Ogrean, G. Williams, W. Röttgering, H. Dawson, W. Forman, W. Gasperin, F. Hardcastle, M. Jones, C. Miley, G. Rafferty, D. Rudnick, L. Sabater, J. Sarazin, C. Shimwell, T. Bonafede, A. Best, P. Birzan, L. Cassano, R. Chyzy, K. Croston, J. Dijkema, T. Enßlin, T. Ferrari, C. Heald, G. Hoeft, M. Horellou, C. Jarvis, M. Kraft, R. Mevius, M. Intema, Hubertus Murray, S. Orrú, E. Pizzo, R. Sridhar, S. Simionescu, A. Stroe, A. Tol, S. White, G. |
| author_sort | Van Weeren, R. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We present deep LOFAR observations between 120 and 181 MHz of the "Toothbrush" (RX J0603.3+4214), a cluster that contains one of the brightest radio relic sources known. Our LOFAR observations exploit a new and novel calibration scheme to probe 10 times deeper than any previous study in this relatively unexplored part of the spectrum. The LOFAR observations, when combined with VLA, GMRT, and Chandra X-ray data, provide new information about the nature of cluster merger shocks and their role in re-accelerating relativistic particles. We derive a spectral index of at the northern edge of the main radio relic, steepening toward the south to . The spectral index of the radio halo is remarkably uniform (, with an intrinsic scatter of ). The observed radio relic spectral index gives a Mach number of , assuming diffusive shock acceleration. However, the gas density jump at the northern edge of the large radio relic implies a much weaker shock (, with an upper limit of ). The discrepancy between the Mach numbers calculated from the radio and X-rays can be explained if either (i) the relic traces a complex shock surface along the line of sight, or (ii) if the radio relic emission is produced by a re-accelerated population of fossil particles from a radio galaxy. Our results highlight the need for additional theoretical work and numerical simulations of particle acceleration and re-acceleration at cluster merger shocks. |
| first_indexed | 2025-11-14T11:00:39Z |
| format | Journal Article |
| id | curtin-20.500.11937-74391 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T11:00:39Z |
| publishDate | 2016 |
| publisher | Institute of Physics Publishing |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-743912019-07-22T05:43:48Z LOFAR, VLA, and Chandra Observations of the Toothbrush Galaxy Cluster Van Weeren, R. Brunetti, G. Brüggen, M. Andrade-Santos, F. Ogrean, G. Williams, W. Röttgering, H. Dawson, W. Forman, W. Gasperin, F. Hardcastle, M. Jones, C. Miley, G. Rafferty, D. Rudnick, L. Sabater, J. Sarazin, C. Shimwell, T. Bonafede, A. Best, P. Birzan, L. Cassano, R. Chyzy, K. Croston, J. Dijkema, T. Enßlin, T. Ferrari, C. Heald, G. Hoeft, M. Horellou, C. Jarvis, M. Kraft, R. Mevius, M. Intema, Hubertus Murray, S. Orrú, E. Pizzo, R. Sridhar, S. Simionescu, A. Stroe, A. Tol, S. White, G. We present deep LOFAR observations between 120 and 181 MHz of the "Toothbrush" (RX J0603.3+4214), a cluster that contains one of the brightest radio relic sources known. Our LOFAR observations exploit a new and novel calibration scheme to probe 10 times deeper than any previous study in this relatively unexplored part of the spectrum. The LOFAR observations, when combined with VLA, GMRT, and Chandra X-ray data, provide new information about the nature of cluster merger shocks and their role in re-accelerating relativistic particles. We derive a spectral index of at the northern edge of the main radio relic, steepening toward the south to . The spectral index of the radio halo is remarkably uniform (, with an intrinsic scatter of ). The observed radio relic spectral index gives a Mach number of , assuming diffusive shock acceleration. However, the gas density jump at the northern edge of the large radio relic implies a much weaker shock (, with an upper limit of ). The discrepancy between the Mach numbers calculated from the radio and X-rays can be explained if either (i) the relic traces a complex shock surface along the line of sight, or (ii) if the radio relic emission is produced by a re-accelerated population of fossil particles from a radio galaxy. Our results highlight the need for additional theoretical work and numerical simulations of particle acceleration and re-acceleration at cluster merger shocks. 2016 Journal Article http://hdl.handle.net/20.500.11937/74391 10.3847/0004-637X/818/2/204 Institute of Physics Publishing fulltext |
| spellingShingle | Van Weeren, R. Brunetti, G. Brüggen, M. Andrade-Santos, F. Ogrean, G. Williams, W. Röttgering, H. Dawson, W. Forman, W. Gasperin, F. Hardcastle, M. Jones, C. Miley, G. Rafferty, D. Rudnick, L. Sabater, J. Sarazin, C. Shimwell, T. Bonafede, A. Best, P. Birzan, L. Cassano, R. Chyzy, K. Croston, J. Dijkema, T. Enßlin, T. Ferrari, C. Heald, G. Hoeft, M. Horellou, C. Jarvis, M. Kraft, R. Mevius, M. Intema, Hubertus Murray, S. Orrú, E. Pizzo, R. Sridhar, S. Simionescu, A. Stroe, A. Tol, S. White, G. LOFAR, VLA, and Chandra Observations of the Toothbrush Galaxy Cluster |
| title | LOFAR, VLA, and Chandra Observations of the Toothbrush Galaxy Cluster |
| title_full | LOFAR, VLA, and Chandra Observations of the Toothbrush Galaxy Cluster |
| title_fullStr | LOFAR, VLA, and Chandra Observations of the Toothbrush Galaxy Cluster |
| title_full_unstemmed | LOFAR, VLA, and Chandra Observations of the Toothbrush Galaxy Cluster |
| title_short | LOFAR, VLA, and Chandra Observations of the Toothbrush Galaxy Cluster |
| title_sort | lofar, vla, and chandra observations of the toothbrush galaxy cluster |
| url | http://hdl.handle.net/20.500.11937/74391 |