A spatially resolved spectral analysis of giant radio galaxies with MeerKAT
| dc.contributor.author | Charlton , K.K.L. | |
| dc.contributor.author | Delhaize, J. | |
| dc.contributor.author | Thorat, Kshitij | |
| dc.contributor.author | Heywood, I. | |
| dc.contributor.author | Jarvis , M.J. | |
| dc.contributor.author | Hardcastle, M.J. | |
| dc.contributor.author | An, F. | |
| dc.contributor.author | Delvecchio, I. | |
| dc.contributor.author | Hale, C.L. | |
| dc.contributor.author | Whittam, I.H. | |
| dc.contributor.author | Bruggen, M. | |
| dc.contributor.author | Marchetti, L. | |
| dc.contributor.author | Morabito, L. | |
| dc.contributor.author | Randriamanakoto, Z. | |
| dc.contributor.author | White, S.V. | |
| dc.contributor.author | Taylor, A.R. | |
| dc.date.accessioned | 2026-04-16T12:28:19Z | |
| dc.date.available | 2026-04-16T12:28:19Z | |
| dc.date.issued | 2025 | |
| dc.description | DATA AVAILABILITY : The data underlying this article were accessed from the South African Radio Astronomy Observatory (SARAO; www.sarao.ac.za ). Upon publication, the radio images from MIGHTEE DR1 will be accessible through: https:// doi.org/ 10.48479/7msw-r692 . The MeerKAT UHF- COSMOS fits image cutouts generated in this research will be shared upon reasonable request: please contact the PI of the data (J. Delhaize; drjdelhaize@gmail.com). The raw MeerKAT visibilities for which any proprietary period has expired can be obtained from the SARAO archive at https://archive.sarao.ac.za . | |
| dc.description.abstract | In this study we report the spatially resolved, wideband spectral properties of three giant radio galaxies (GRGs) in the COSMOS field: MGTC J095959.63 + 024608.6, MGTC J100016.84 + 015133.0, and MGTC J100022.85 + 031520.4. One of these galaxies, MGTC J100022.85 + 031520.4, is reported here for the first time, with a projected linear size of 1.29 Mpc at a redshift of 0.1034. Unlike the other two, it is associated with a brightest cluster galaxy (BCG), making it one of the few GRGs known to inhabit cluster environments. We examine the spectral age distributions of the three GRGs using new MeerKAT UHF-band (544–1088 MHz) observations, and L -band (900–1670 MHz) data from the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) survey. We test two models of spectral ageing, the Jaffe–Perola and Tribble models, using the Broadband Radio Astronomy Tools ( BRATS ) software, and find that they agree well with each other. We estimate the Tribble spectral age for MGTC J095959.63 + 024608.6 as 68 Myr, for MGTC J100016.84 + 015133.0 as 47 Myr, and for MGTC J100022.85 + 031520.4 as 67 Myr. We find significant disagreements between these spectral age estimates and the estimates of the dynamical ages of these GRGs, modelled in cluster and group environments. Our results highlight the need for additional processes that are not accounted for in either the dynamic age or the spectral age estimations. | |
| dc.description.department | Physics | |
| dc.description.librarian | am2026 | |
| dc.description.sdg | SDG-03: Good health and well-being | |
| dc.description.sponsorship | FUNDING : We thank the anonymous referee for useful suggestions, which impro v ed this paper . KC’ s research is supported by the South African Radio Astronomy Observatory (SARAO). JD, KC, MJ, and IH acknowledge support from an Africa–Oxford Catalyst Collaboration Grant (AfOx-290), which made this research possible. JD also acknowledges support from a UCT Research Development Grant. MJJ, IHW, and CLH acknowledge generous support from the Hintze Family Charitable Foundation through the Oxford Hintze Centre for Astrophysical Surveys. MJJ and IH also acknowledge support from a UKRI Frontiers Research Grant (EP/X026639/1), which was selected by the ERC, and the UK Science and Technology Facilities Council (ST/S000488/1). FXA acknowledges support from the National Natural Science Foundation of China (12303016) and the Natural Science Foundation of Jiangsu Province (BK20242115). ID acknowledges funding from the European Union –NextGenerationEU, RRF M4C2 1.1, PRIN 2022JZJBHM: ’AGN-sCAN: zooming-in on the AGN-galaxy connection since the cosmic noon’ –CUP C53D23001120006. The MeerKAT telescope is operated by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation. We acknowledge the use of the ilifu cloud computing facility , www .ilifu.ac.za , a partnership between the University of Cape Town, the University of the Western Cape, Stellenbosch University, Sol Plaatje University, and the Cape Peninsula University of Technology. The ilifu facility is supported by contributions from the Inter-University Institute for Data Intensive Astronomy (IDIA, a partnership between the University of Cape Town, the University of Pretoria, and the University of the Western Cape), the Computational Biology division at UCT, and the Data Intensive Research Initiative of South Africa (DIRISA). This work made use of the CARTA (Cube Analysis and Rendering Tool for Astronomy) software (DOI 10.5281/zenodo.3377984 –ht tps://cartavis.git hub.io ). Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the US Department of Energy Office of Science. The SDSS-III website is http:// www.sdss3.org/ .S DSS-III and is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS-III Collaboration, including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrofisica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington, and Yale University. This work is based on the research supported in part by the National Research Foundation of South Africa (Grant Number 151060).The Hyper Suprime-Cam (HSC) collaboration includes the astronomical communities of Japan and Taiwan, and Princeton University. The HSC instrumentation and software were developed by the National Astronomical Observatory of Japan (NAOJ), the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), the University of Tokyo, the High Energy Accelerator Research Organization (KEK), the Academia Sinica Institute for Astronomy and Astrophysics in Taiwan (ASIAA), and Princeton University. Funding was contributed by the FIRST program from the Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Society for the Promotion of Science (JSPS), the Japan Science and Technology Agency (JST), the Toray Science Foundation, NAOJ, Kavli IPMU, KEK, ASIAA, and Princeton University. | |
| dc.description.uri | https://academic.oup.com/mnras | |
| dc.identifier.citation | Charlton, K.K.L., Delhaize, J., Thorat, K. 2025, 'A spatially resolved spectral analysis of giant radio galaxies with MeerKAT', Monthly Notices of the Royal Astronomical Society, vol. 537, pp. 272-284. https://doi.org/10.1093/mnras/stae2543. | |
| dc.identifier.issn | 0035-8711 (print) | |
| dc.identifier.issn | 1365-2966 (online) | |
| dc.identifier.other | 10.1093/mnras/stae2543 | |
| dc.identifier.uri | http://hdl.handle.net/2263/109620 | |
| dc.language.iso | en | |
| dc.publisher | Oxford University Press | |
| dc.rights | © The Author(s) 2025. This article is licensed under a Creative Commons Attribution 4.0 International License. | |
| dc.subject | Methods: observational | |
| dc.subject | Galaxies: active | |
| dc.subject | Galaxies: evolution | |
| dc.subject | Galaxies: nuclei | |
| dc.subject | Radio continuum: galaxies | |
| dc.title | A spatially resolved spectral analysis of giant radio galaxies with MeerKAT | |
| dc.type | Article |