A $\mathcal{M}\gtrsim 3$ shock in `El Gordo' cluster and the origin of the radio relic

Abstract

We present an X-ray and radio study of the famous `El Gordo', a massive and distant ($z=0.87$) galaxy cluster. In the deep (340 ks) Chandra observation, the cluster appears with an elongated and cometary morphology, a sign of its current merging state. The GMRT radio observations at 610 MHz reveal the presence of a radio halo which remarkably overlaps the X-ray cluster emission and connects a couple of radio relics. We detect a strong shock ($\mathcal{M}\gtrsim 3$) in the NW periphery of the cluster, co-spatially located with the radio relic. This is the most distant ($z=0.87$) and one of the strongest shock detected in a galaxy cluster. This work supports the relic-shock connection and allows to investigate the origin of these radio sources in a uncommon regime of $\mathcal{M}\gtrsim 3$. For this particular case we found that shock acceleration from the thermal pool is still a viable possibility.

10 pages, 8 figures, 2 tables; Updated to match the accepted version in MNRAS; Results unchanged

References in corpus (14)

• Shocks and cold fronts in galaxy clusters
• Particle Acceleration on Megaparsec Scales in a Merging Galaxy Cluster
• Non-Thermal Electron Acceleration in Low Mach Number Collisionless Shocks. I. Particle Energy Spectra and Acceleration Mechanism
• Double relics in Abell 2345 and Abell 1240: spectral index and polarization analysis
• The Atacama Cosmology Telescope: Physical Properties and Purity of a Galaxy Cluster Sample Selected via the Sunyaev-Zel'dovich Effect
• A new double radio relic in PSZ1 G096.89+24.17 and a radio relic mass-luminosity relation
• Non-Thermal Electron Acceleration in Low Mach Number Collisionless Shocks. II. Firehose-Mediated Fermi Acceleration and its Dependence on Pre-Shock Conditions
• Shock heating of the merging galaxy cluster A521
• Chandra observation of two shock fronts in the merging galaxy cluster Abell 2146
• Chandra ACIS-I particle background: an analytical model
• A Hydrodynamical Solution for the "Twin-Tailed" Colliding Galaxy Cluster "El Gordo"
• A NuSTAR observation of the center of the Coma Cluster
• Nonthermal hard X-ray excess in the Coma cluster: resolving the discrepancy between the results of different PDS data analyses
• Injection of $\kappa$-like Suprathermal Particles into Diffusive Shock Acceleration

Cited by in corpus (40)

• Diffuse Radio Emission from Galaxy Clusters
• LOFAR observations of galaxy clusters in HETDEX
• The MeerKAT Galaxy Cluster Legacy Survey I. Survey Overview and Highlights
• Deep VLA observations of the cluster 1RXS J0603.3+4214 in the frequency range 1-2 GHz
• Dissecting nonthermal emission in the complex multiple-merger galaxy cluster Abell 2744: Radio and X-ray analysis
• Exploring the spectral properties of radio relics I: Integrated spectral index and Mach number
• Polarisation of Radio Relics in Galaxy Clusters
• Deep low-frequency radio observations of Abell 2256 I: The filamentary radio relic
• The LOFAR and JVLA view of the distant steep spectrum radio halo in MACS J1149.5+2223
• Radio fossils, relics, and haloes in Abell 3266: cluster archaeology with ASKAP-EMU and the ATCA
• ALMA-SZ Detection of a Galaxy Cluster Merger Shock at Half the Age of the Universe
• A Robust Model for Flux Density Calculations of Radio Halos in Galaxy Clusters: Halo-FDCA
• Understanding the radio relic emission in the galaxy cluster MACS J0717.5+3745: spectral analysis
• Discovery of a Supercluster in the eROSITA Final Equatorial Depth Survey: X-ray Properties, Radio Halo, and Double Relics
• The Planck clusters in the LOFAR sky VI. LoTSS-DR2: Properties of radio relics
• Analytical model for cluster radio relics
• Observations of the galaxy cluster CIZA J2242.8+5301 with the Sardinia Radio Telescope
• A Study of High-redshift AGN Feedback in SZ Cluster Samples
• Evidence for a merger induced shock wave in ZwCl\,0008.8+5215 with {\it Chandra} and {\it Suzaku}
• Turbulent magnetic fields in the merging galaxy cluster MACS J0717.5+3745: polarization analysis
• Synchrotron Intensity Gradient Revealing Magnetic Fields in Galaxy Clusters
• Discovery of a pre-merger shock in an intercluster filament in Abell 98
• Radio relics in PSZ2 G096.88+24.18: A connection with pre-existing plasma
• A MUSE view of the massive merging galaxy cluster ACT-CL J0102-4915 (El Gordo) at z = 0.87: robust strong lensing model and data release
• A Massive Cluster at z = 0.288 Caught in the Process of Formation: The Case of Abell 959
• Surface brightness discontinuities in radio halos. Insights from the MeerKAT Galaxy Cluster Legacy Survey
• SPT-CL J2032-5627: a new Southern double relic cluster observed with ASKAP
• Diffuse radio emission in MACS J0025.4$-$1222: the effect of a major merger on bulk separation of ICM components
• The correlation between radio power and Mach number for radio relics in galaxy clusters
• Abell 1430: A merging cluster with exceptional diffuse radio emission
• On the Challenges of Cosmic-Ray Proton Shock Acceleration in the Intracluster Medium
• Unveiling The Origin of Peculiar Diffuse Radio Emission in Abell 1351
• Double radio relics and radio halo in the high redshift galaxy cluster El Gordo with the Upgraded GMRT
• Complex diffuse emission in the $z=0.52$ cluster PLCK~G004.5-19.5
• Protruding bullet heads indicating dark matter pull
• A Pre-Merger Stage Galaxy Cluster: Abell 3733
• Chandra observations of the Abell S0295 cluster
• Deciphering the spectral properties of the atypical radio relic in A115 using uGMRT, VLA, and LOFAR
• Low-frequency integrated radio spectra of diffuse, steep-spectrum sources in galaxy clusters: palaeontology with the MWA and ASKAP
• A high-resolution study of the double radio relic system in MACS J1752.0+4440