The discovery of radio halos in the Frontier Fields clusters Abell S1063 and Abell 370

Abstract

Massive merging galaxy clusters often host diffuse Mpc-scale radio synchrotron emission. This emission originates from relativistic electrons in the ionized intracluster medium (ICM). An important question is how these synchrotron emitting relativistic electrons are accelerated. Our aim is to search for diffuse emission in the Frontier Fields clusters Abell S1063 and Abell 370 and characterize its properties. While these clusters are very massive and well studied at some other wavelengths, no diffuse emission has been reported for these clusters so far. We obtained 325 MHz Giant Metrewave Radio Telescope (GMRT) and 1--4 GHz Jansky Very Large Array (VLA) observations of Abell S1063 and Abell 370. We complement these data with Chandra and XMM-Newton X-ray observations. In our sensitive images, we discover radio halos in both clusters. In Abell S1063, a giant radio halo is found with a size of $\sim 1.2$ Mpc. The integrated spectral index between 325 MHz and 1.5 GHz is $-0.94\pm 0.08$ and it steepens to $-1.77\pm 0.20$ between 1.5 and 3.0 GHz. This spectral steepening provides support for the turbulent re-acceleration model for radio halo formation. Abell 370 hosts a faint radio halo mostly centred on the southern part of this binary merging cluster, with a size of $\sim 500-700$ kpc. The spectral index between 325 MHz and 1.5 GHz is $-1.10\pm 0.09$. Both radio halos follow the known scaling relation between the cluster mass proxy $Y_{500}$ and radio power, consistent with the idea that they are related to ongoing cluster merger events.

12 pages, 13 figures, 4 tables; resubmitted to A&A after incorporating reviewer's comments

References in corpus (23)

• Chandra temperature profiles for a sample of nearby relaxed galaxy clusters
• Multi-Scale CLEAN deconvolution of radio synthesis images
• Diffuse Radio Emission from Galaxy Clusters
• On the connection between giant radio halos and cluster mergers
• A low-frequency radio halo associated with a cluster of galaxies
• GMRT Radio Halo Survey in galaxy clusters at z = 0.2 -- 0.4 I.The REFLEX sub--sample
• Statistics of Giant Radio Halos from Electron Reacceleration Models
• Do radio core-halos and cold fronts in non major merging clusters originate from the same gas sloshing?
• X-Ray morphological analysis of the Planck ESZ clusters
• Double relics in Abell 2345 and Abell 1240: spectral index and polarization analysis
• Turbulence and Particle Acceleration in Giant Radio Haloes: the Origin of Seed Electrons
• Relativistic protons in the Coma galaxy cluster: first gamma-ray constraints ever on turbulent reacceleration
• The Extended GMRT Radio Halo Survey II: Further results and analysis of the full sample
• Deep VLA observations of the cluster 1RXS J0603.3+4214 in the frequency range 1-2 GHz
• X-ray and Sunyaev-Zel'dovich scaling relations in galaxy clusters
• VLA Radio Observations of the HST Frontier Fields Cluster Abell 2744: The Discovery of New Radio Relics
• Chandra and JVLA observations of HST Frontier Fields cluster MACS J0717.5+3745
• Nonthermal Emission Associated with Strong AGN Outbursts at the Centers of Galaxy Clusters
• New giant radio sources and underluminous radio halos in two galaxy clusters
• X-ray Point Sources and Radio Galaxies in Clusters of Galaxies
• A radio halo surrounding the Brightest Cluster Galaxy in RXCJ0232.2-4420: a mini-halo in transition ?
• A distant radio mini-halo in the Phoenix galaxy cluster
• ATCA observations of the MACS-Planck Radio Halo Cluster Project - I. New detection of a radio halo in PLCK G285.0-23.7

Cited by in corpus (25)

• The MeerKAT Galaxy Cluster Legacy Survey I. Survey Overview and Highlights
• The beautiful mess in Abell 2255
• New mysteries and challenges from the Toothbrush relic: wideband observations from 550 MHz to 8 GHz
• Physical insights from the spectrum of the radio halo in MACS J0717.5+3745
• CLASH-VLT: Abell~S1063. Cluster assembly history and spectroscopic catalogue
• Radio and X-ray connection in radio mini-halos: implications for hadronic models
• Simulating the transport of relativistic electrons and magnetic fields injected by radio galaxies in the intracluster medium
• The LOFAR and JVLA view of the distant steep spectrum radio halo in MACS J1149.5+2223
• Observing ram pressure at work in intermediate redshift clusters with MUSE: the case of Abell 2744and Abell 370
• Deep low-frequency radio observations of Abell 2256 II: The ultra-steep spectrum radio halo
• A MeerKAT-meets-LOFAR study of Abell 1413: a moderately disturbed non-cool-core cluster hosting a $\sim 500$ kpc 'mini'-halo
• The intracluster light on Frontier Fields clusters Abell 370 and Abell S1063
• An X-ray and Radio Study of the Hubble Frontier Field Cluster Abell S1063
• The diffuse radio emission in the high-redshift cluster PSZ2 G091.83+26.11: total intensity and polarisation analysis with Very Large Array 1-4 GHz observations
• Very Large Array observations of the mini-halo and AGN feedback in the Phoenix cluster
• Radio halos and relics from extended cosmic-ray ion distributions with strong diffusion in galaxy clusters
• Probing particle acceleration in Abell 2256: from to 16 MHz to gamma rays
• Double radio relics and radio halo in the high redshift galaxy cluster El Gordo with the Upgraded GMRT
• Spectral study of the diffuse synchrotron source in the galaxy cluster Abell 523
• Effects of large-scale magnetic fields on the observed composition of ultra high-energy cosmic rays
• CHEX-MATE: New detections and properties of the radio diffuse emission in massive clusters with MeerKAT
• Star Formation, Nebulae, and Active Galactic Nuclei in CLASH Brightest Cluster Galaxies. I. Dependence on Core Entropy of Intracluster Medium
• Combined LOFAR-uGMRT analysis of the diffuse radio emission in the massive clusters Abell 773 and Abell 1351
• uGMRT and MeerKAT observation of RXCJ0232-4420: a quiet cluster with a giant radio halo
• Discovery of large-scale radio emission enveloping the mini-halo in the most X-ray luminous galaxy cluster RX~J1347.5-1145