Discovery of a radio halo (and relic) in a $M_{500}<2\times 10^{14}$ M${}_{\odot }$ cluster

Abstract

Radio halos are diffuse synchrotron sources observed in dynamically unrelaxed galaxy clusters. Current observations and models suggest that halos trace turbulent regions in the intra-cluster medium where mildly relativistic particles are re-accelerated during cluster mergers. Due to the higher luminosities and detection rates with increasing cluster mass, radio halos have been mainly observed in massive systems ($M_{500}\gtrsim 5\times 10^{14}$ M${}_{\odot }$). Here, we report the discovery of a radio halo with a largest linear scale of $\simeq$750 kpc in PSZ2G145.92-12.53 ($z=0.03$) using LOFAR observations at 120$-$168 MHz. With a mass of $M_{500}=(1.9\pm 0.2)\times 10^{14}$ M${}_{\odot }$ and a radio power at 150 MHz of $P_{150}=(3.5\pm 0.7)\times 10^{23}$ W/Hz, this is the least powerful radio halo in the least massive cluster discovered to date. Additionally, we discover a radio relic with a mildly convex morphology at $\sim$1.7 Mpc from the cluster center. Our results demonstrate that LOFAR has the potential to detect radio halos even in low-mass clusters, where the expectation to form them is very low ($\sim$5%) based on turbulent re-acceleration models. Together with the observation of large samples of clusters, this opens the possibility to constrain the low end of the power-mass relation of radio halos.

arXiv comment8 pages, 5 figures, 1 table (including appendix). Accepted for publication in ApJL

References in corpus (47)

• LOFAR: The LOw-Frequency ARray
• WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
• The eROSITA X-ray telescope on SRG
• The LOFAR Two-metre Sky Survey - I. Survey Description and Preliminary Data Release
• Clusters of galaxies : observational properties of the diffuse radio emission
• The LOFAR Two-metre Sky Survey - II. First data release
• The MCXC: a Meta-Catalogue of X-ray detected Clusters of galaxies
• Cosmic rays in galaxy clusters and their non-thermal emission
• Planck 2013 results. XXIX. Planck catalogue of Sunyaev-Zeldovich sources
• Magnetic Field in Clusters of Galaxies
• Diffuse Radio Emission from Galaxy Clusters
• LOFAR facet calibration
• The LOFAR Two Meter Sky Survey: Deep Fields, I -- Direction-dependent calibration and imaging
• Cluster mergers and non-thermal phenomena: expectations from a statistical magneto-turbulent model
• Revisiting scaling relations for giant radio halos in galaxy clusters
• Systematic effects in LOFAR data: A unified calibration strategy
• 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
• Radio halos in nearby (z < 0.4) clusters of galaxies
• LOFAR observations of galaxy clusters in HETDEX
• Comparative analysis of the diffuse radio emission in the galaxy clusters A1835, A2029, and Ophiuchus
• A new double radio relic in PSZ1 G096.89+24.17 and a radio relic mass-luminosity relation
• On the occurrence of Radio Halos in galaxy clusters - Insight from a mass-selected sample
• The Extended GMRT Radio Halo Survey II: Further results and analysis of the full sample
• Unveiling radio halos in galaxy clusters in the LOFAR era
• Spectral properties and origin of the radio halo in A3562
• The Extended GMRT Radio Halo Survey I: New upper limits on radio halos and mini-halos
• Radio halos in a mass-selected sample of 75 galaxy clusters. II. Statistical analysis
• Radio Properties of the Shapley Concentration. III. Merging Clusters in the A3558 Complex
• Why are central radio relics so rare?
• Fast magnetic field amplification in distant galaxyclusters
• Can cluster merger shocks reproduce the luminosity and shape distribution of radio relics?
• The radio halo in the merging cluster A3562
• An Objective Survey of Mpc-Scale Radio Emission in 0.03<z<0.3 Bright X-ray Clusters
• The contribution of discrete sources to the sky temperature at 144 MHz
• Particle acceleration in a nearby galaxy cluster pair: the role of cluster dynamics
• A Robust Model for Flux Density Calculations of Radio Halos in Galaxy Clusters: Halo-FDCA
• Analytical model for cluster radio relics
• KAT-7 observations of a mass-selected sample of galaxy clusters
• Twin radio relics in a near-by low-mass galaxy cluster Abell 168
• Mystery solved: discovery of extended radio emission in the merging galaxy cluster Abell 2146
• Diffuse galaxy cluster emission at 168 MHz within the Murchison Widefield Array Epoch of Reionization 0-hour field
• Nonthermal phenomena in the center of Abell 1775: An 800 kpc head-tail, revived fossil plasma and slingshot radio halo
• Diffuse Radio Emission from Galaxy Clusters in the LOFAR Two-metre Sky Survey Deep Fields
• Characterizing the radio emission from the binary galaxy cluster merger Abell 2146
• LOFAR discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45
• LOFAR Detection of a Low-Power Radio Halo in the Galaxy Cluster Abell 990

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• The Planck clusters in the LOFAR sky. I. LoTSS-DR2: new detections and sample overview
• The Planck clusters in the LOFAR sky: IV: LoTSS-DR2: statistics of radio halos and re-acceleration models
• Radio fossils, relics, and haloes in Abell 3266: cluster archaeology with ASKAP-EMU and the ATCA
• The Planck clusters in the LOFAR sky VI. LoTSS-DR2: Properties of radio relics
• Abell 1033: Radio halo and gently reenergized tail at 54 MHz
• LOFAR high-band antenna observations of the Perseus cluster
• The prototypical major cluster merger Abell 754. I. Calibration of MeerKAT data and radio/X-ray spectral mapping of the cluster
• Diffuse radio emission from non-Planck galaxy clusters in the LoTSS-DR2 fields
• Exploring diffuse radio emission in galaxy clusters and groups with the uGMRT and the SKA
• A formation mechanism for "Wrong Way" Radio Relics
• Inflationary and phase-transitional primordial magnetic fields in galaxy clusters
• High-energy neutrino constraints on cosmic-ray re-acceleration in radio halos of massive galaxy clusters
• Post-processing of galaxies due to major cluster mergers I. hints from galaxy colours and morphologies
• Optical/X-ray/radio view of Abell 1213: A galaxy cluster with anomalous diffuse radio emission
• Radio emission from a massive node of the cosmic web. A discovery powered by machine learning
• Somewhere in between: Tracing the Radio Emission from Galaxy Groups (or Why Does the Future of Observing Galaxy Groups with Radio Telescopes Look Promising?)