The MeerKAT Massive Distant Clusters Survey: A Radio Halo in a Massive Galaxy Cluster at z = 1.23

2024/04/05 by S. P. Sikhosana, Sikhosana, S. P., Matt Hilton +21 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Stellar, planetary, and galactic studies

paper · pdf · doi:10.48550/arxiv.2404.03944

openalex publication_date 2024/04/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

In the current 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 α^1.3GHz_0.8GHz = 1.3 ± 0.4 and a radio power of P_1.4GHz = (4.4 ± 1.5) × 10²⁴ W Hz^-1. This result further confirms that there is rapid magnetic field amplification in galaxy clusters at high redshift.

Cited by

• An Active Galaxy Cluster Merger at Cosmic Noon Revealed by JWST Weak Lensing and Multiwavelength Probes
• Discovery of Diffuse Radio Emission in a Massive z=1.709 Cool Core Cluster: A Candidate Radio Mini-Halo

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