Abell 3266 is a massive and complex merging galaxy cluster that exhibits significant substructure. We present new, highly sensitive radio continuum observations of Abell 3266 performed with the Australian Square Kilometre Array Pathfinder (0.8–1.1 GHz) and the Australia Telescope Compact Array (1.1–3.1 GHz). These deep observations provide new insights into recently reported diffuse non-thermal phenomena associated with the intracluster medium, including a ‘wrong-way’ relic, a fossil plasma source, and an as-yet unclassified central diffuse ridge, which we reveal comprises the brightest part of a large-scale radio halo detected here for the first time. The ‘wrong-way’ relic is highly atypical of its kind: it exhibits many classical signatures of a shock-related radio relic, while at the same time exhibiting strong spectral steepening. While radio relics are generally consistent with a quasi-stationary shock scenario, the ‘wrong-way’ relic is not. We study the spectral properties of the fossil plasma source; it exhibits an ultrasteep and highly curved radio spectrum, indicating an extremely aged electron population. The larger scale radio halo fills much of the cluster centre, and presents a strong connection between the thermal and non-thermal components of the intracluster medium, along with evidence of substructure. Whether the central diffuse ridge is simply a brighter component of the halo, or a mini-halo, remains an open question. Finally, we study the morphological and spectral properties of the multiple complex radio galaxies in this cluster in unprecedented detail, tracing their evolutionary history.
Riseley, C. J., et al. "Radio fossils, relics, and haloes in Abell 3266: cluster archaeology with ASKAP-EMU and the ATCA." Monthly Notices of the Royal Astronomical Society, vol. 515, no. 2, Aug. 2022. https://doi.org/10.1093/mnras/stac1771
Riseley, C. J., Bonnassieux, E., Vernstrom, T., Galvin, T. J., Chokshi, A., Botteon, A., Rajpurohit, K., Duchesne, S. W., Bonafede, A., Rudnick, L., Hoeft, M., Quici, B., Eckert, D., Brienza, M., Tasse, C., Carretti, E., Collier, J. D., Diego, J. M., ... Reiprich, T. H. (2022). Radio fossils, relics, and haloes in Abell 3266: cluster archaeology with ASKAP-EMU and the ATCA. Monthly Notices of the Royal Astronomical Society, 515(2). https://doi.org/10.1093/mnras/stac1771
Riseley, C. J., Bonnassieux, E., Vernstrom, T., et al., "Radio fossils, relics, and haloes in Abell 3266: cluster archaeology with ASKAP-EMU and the ATCA," Monthly Notices of the Royal Astronomical Society 515, no. 2 (2022), https://doi.org/10.1093/mnras/stac1771
@article{osti_1879154,
author = {Riseley, C. J. and Bonnassieux, E. and Vernstrom, T. and Galvin, T. J. and Chokshi, A. and Botteon, A. and Rajpurohit, K. and Duchesne, S. W. and Bonafede, A. and Rudnick, L. and others},
title = {Radio fossils, relics, and haloes in Abell 3266: cluster archaeology with ASKAP-EMU and the ATCA},
annote = {ABSTRACT Abell 3266 is a massive and complex merging galaxy cluster that exhibits significant substructure. We present new, highly sensitive radio continuum observations of Abell 3266 performed with the Australian Square Kilometre Array Pathfinder (0.8–1.1 GHz) and the Australia Telescope Compact Array (1.1–3.1 GHz). These deep observations provide new insights into recently reported diffuse non-thermal phenomena associated with the intracluster medium, including a ‘wrong-way’ relic, a fossil plasma source, and an as-yet unclassified central diffuse ridge, which we reveal comprises the brightest part of a large-scale radio halo detected here for the first time. The ‘wrong-way’ relic is highly atypical of its kind: it exhibits many classical signatures of a shock-related radio relic, while at the same time exhibiting strong spectral steepening. While radio relics are generally consistent with a quasi-stationary shock scenario, the ‘wrong-way’ relic is not. We study the spectral properties of the fossil plasma source; it exhibits an ultrasteep and highly curved radio spectrum, indicating an extremely aged electron population. The larger scale radio halo fills much of the cluster centre, and presents a strong connection between the thermal and non-thermal components of the intracluster medium, along with evidence of substructure. Whether the central diffuse ridge is simply a brighter component of the halo, or a mini-halo, remains an open question. Finally, we study the morphological and spectral properties of the multiple complex radio galaxies in this cluster in unprecedented detail, tracing their evolutionary history.},
doi = {10.1093/mnras/stac1771},
url = {https://www.osti.gov/biblio/1879154},
journal = {Monthly Notices of the Royal Astronomical Society},
issn = {ISSN 0035-8711},
number = {2},
volume = {515},
place = {United Kingdom},
publisher = {Oxford University Press},
year = {2022},
month = {08}}
Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN (United States)
Sponsoring Organization:
German Research Foundation (DFG); Higher Education Funding Council for England; Ministry of Science and Education of Spain; National Science Foundation (NSF); Science and Technology Facilities Council of the United Kingdom; Texas University; USDOE; USDOE Office of Science (SC)
Grant/Contract Number:
SC0014664
OSTI ID:
1879154
Alternate ID(s):
OSTI ID: 1982629
Journal Information:
Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 2 Vol. 515; ISSN 0035-8711