J/A+A/698/L17ivo://CDS.VizieR/J/A+A/698/L17doi:10.26093/cds/vizier/bc-nt/wbhCDSSikhosana S.P.Hilton M.Bernardi G.Kesebonye K.Klutse D.Y.,Knowles K.Moodley K.Mroczkowski T.Oozeer N.Partridge B.,Phuravhathu D.Sifon C.Vargas C.Wollack E.2026-08-03T06:55:13Z2025-06-11T10:06:18ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxy-clustersradio-sourcesIn the current theoretical paradigm, high redshift radio halos are expected to be scarce due to inverse Compton energy losses and redshift dimming, which cause them to be intrinsically faint. This low occurrence fraction is predicted by cosmic ray electron turbulent re-acceleration models. To date, only a handful of radio halos have been detected at redshift z>0.8. We report the MeerKAT detection of a radio halo hosted by a galaxy cluster ACT-CL J0329.2-2330 at z=1.23, making it the highest redshift halo detected thus far. Using L-band and UHF-band observations, we derive a radio halo spectral index of {alpha}^1.3GHz^_0.8GHz_=1.3+/-0.4 and a radio power of P_1.4_GHz=(4.4+/-1.5(x10^24^W/Hz/ This result further confirms that there is rapid magnetic field amplification in galaxy clusters at high redshift.2025A&A...698L..17Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/698/L17CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/698/L17https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/698/L17http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/698/L17https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/698/L17https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/698/L17http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/698/L17GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/698/L17/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/698/L17/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/698/L17/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/698/L17/list?GETtext/xml+votable180.050000true52.3236-23.502850.0055555555555555566/36142https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/698/L17?format=asciiRadiodefaultJ/A+A/698/L17/listList of fits imagesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintObs.dateObservation datestime.epoch;obsnullableFreqobserved frequencyHzem.freqdoublesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar