Narrow head-tail radio galaxies at very high resolution

Gregory, Beatrice Terni de; Feretti, L.; Giovannini, G.; Govoni, F.; Murgia, M.; Perley, R. A.; Vacca, V.

doi:10.1051/0004-6361/201730878

Cited by 22 publications

(10 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…PSZ2 G031.93+78.71 (A1775) It hosts a prominent head-tail radio galaxy that has been studied in the past (Owen & Ledlow 1997;Giovannini & Feretti 2000;Giacintucci et al 2007;Terni de Gregory et al 2017). The presence in the cluster center of a radio halo bounded by a cold front was recently claimed by Botteon et al (2021b) using LoTSS data, who referred to this emission as a "slingshot" radio halo.…”

Section: Appendix A: Tablesmentioning

confidence: 99%

The Planck clusters in the LOFAR sky. I. LoTSS-DR2: new detections and sample overview

Botteon,

Shimwell,

Cassano

et al. 2022

Preprint

View full text Add to dashboard Cite

Context. Relativistic electrons and magnetic fields permeate the intra-cluster medium (ICM) and manifest themselves as diffuse sources of synchrotron emission observable at radio wavelengths, namely radio halos and radio relics. Although there is broad consensus that the formation of these sources is connected to turbulence and shocks in the ICM, the details of the required particle acceleration, the strength and morphology of the magnetic field in the cluster volume, and the influence of other sources of high-energy particles are poorly known. Aims. Sufficiently large samples of radio halos and relics, which would allow us to examine the variation among the source population and pinpoint their commonalities and differences, are still missing. At present, due to the physical properties of the sources and the capabilities of existing facilities, large numbers of these sources are easiest to detect at low radio frequencies, where they shine brightly. Methods. We examined the low-frequency radio emission from all 309 clusters in the second catalog of Planck Sunyaev Zel'dovich detected sources that lie within the 5634 deg 2 covered by the Second Data Release of the LOFAR Two-meter Sky Survey (LoTSS-DR2). We produced LOFAR images at different resolutions, with and without discrete sources subtracted, and created overlays with optical and X-ray images before classifying the diffuse sources in the ICM, guided by a decision tree. Results. Overall, we found 83 clusters that host a radio halo and 26 that host one or more radio relics (including candidates). About half of them are new discoveries. The detection rate of clusters that host a radio halo and one or more relics in our sample is 30 ± 11% and 10 ± 6%, respectively. Extrapolating these numbers, we anticipate that once LoTSS covers the entire northern sky it will provide the detection of 251 ± 92 clusters that host a halo and 83 ± 50 clusters that host at least one relic from Planck clusters alone. All images and results produced in this work are publicly available via the project website.

show abstract

Section: Appendix A: Tablesmentioning

confidence: 99%

The Planck clusters in the LOFAR sky. I. LoTSS-DR2: new detections and sample overview

Botteon,

Shimwell,

Cassano

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…Radio galaxies (RGs) are found from the cores to the extremities of galaxy clusters (e.g., Kale et al 2015;Padovani 2016;Garon et al 2019). Cluster RGs frequently appear significantly distorted from simple, bilateral, axial symmetry (e.g., Terni de Gregory et al 2017;Garon et al 2019), revealing non-axisymmetric environmental impacts. Sometimes the distortions can be attributed to galaxy motions relative to the cluster center.…”

Section: Introductionmentioning

confidence: 99%

Simulated Interactions between Radio Galaxies and Cluster Shocks. II. Jet Axes Orthogonal to Shock Normals

Nolting

Jones

O'Neill

et al. 2019

ApJ

View full text Add to dashboard Cite

We report a 3D MHD simulation study of the interactions between radio galaxies and galaxy-clustermedia shocks in which the incident shock normals are orthogonal to the bipolar AGN jets. Before shock impact, light, supersonic jets inflate lobes (cavities) in a static, uniform ICM. We examine three AGN activity scenarios: 1) continued, steady jet activity; 2) jet source cycled off coincident with shock/radio lobe impact; 3) jet activity ceased well before shock arrival (a "radio phoenix" scenario). The simulations follow relativistic electrons (CRe) introduced by the jets, enabling synthetic radio synchrotron images and spectra. Such encounters can be decomposed into an abrupt shock transition and a subsequent long term post shock wind. Shock impact disrupts the pre-formed, low density RG cavities into two ring vortices embedded in the post shock wind. Dynamical processes cause the vortex pair to merge as they propagate downwind somewhat faster than the wind itself. When the AGN jets remain active ram pressure bends the jets downwind, generating a narrow angle tail morphology aligned with the axis of the vortex ring. The deflected jets do not significantly alter dynamical evolution of the vortex ring. However, active jets and their associated tails do dominate the synchrotron emission, compromising the observability of the vortex structures. Downwind-directed momentum concentrated by the jets impacts and alters the post-encounter shock. In the "radio phoenix" scenario, no DSA of the fossil electron population is required to account for the observed brightening and flattening of the spectra, adiabatic compression effects are sufficient. arXiv:1909.08721v1 [astro-ph.HE]

show abstract

“…The fainter one is found located about ∼ 1 Mpc southeast to the main X-ray halo (McMillan et al 1989), and both the X-ray halos spatially coinciding with the optical subclusters. Meanwhile, the cluster is a rare case that simultaneously contains two tailed radio galaxies in its central region (< 40 kpc), which have been studied in detail using the Very Large Array (VLA), the Giant Giovannini & Feretti 2000;Giacintucci et al 2007;Terni de Gregory et al 2017;Botteon et al 2021). One of them shows relatively small (∼ 10 or ∼ 14 kpc) bent tails at 1.4 GHz (O'Dea & Owen 1985), which point approximately toward the east.…”

Section: Introductionmentioning

confidence: 99%

The Merger Dynamics of the Galaxy Cluster Abell 1775: New Insights from Chandra and XMM-Newton for a Cluster Simultaneously Hosting a WAT and a NAT Radio Sources

Hu,

Xu,

Zhu

et al. 2021

Preprint

View full text Add to dashboard Cite

We present a new study of the merger dynamics of Abell 1775 by analyzing the high-quality Chandra and XMM-Newton archival data. We confirm/identify an arc-shaped edge (i.e., the head) at ∼ 48 kpc west of the X-ray peak, a split cold gas tail that extends eastward to ∼ 163 kpc, and a plume of spiral-like X-ray excess (within about 81 − 324 kpc northeast of the cluster core) that connects to the end of the tail. The head, across which the projected gas temperature rises outward from 3.39 +0.28 −0.18 keV to 5.30 +0.54 −0.43 keV, is found to be a cold front with a Mach number of M ∼ 0.79. Along the surfaces of the cold front and tail, typical KHI features (noses and wings, etc.) are found and are used to constrain the upper limit of the magnetic field (∼ 11.2 µG) and the viscosity suppression factor (∼ 0.01). Combining optical and radio evidence we propose a two-body merger (instead of systematic motion in a large-scale gas environment) scenario and have carried out idealized hydrodynamic simulations to verify it. We find that the observed X-ray emission and temperature distributions can be best reproduced with a merger mass ratio of 5 after the first pericentric passage. The NAT radio galaxy is thus more likely to be a single galaxy falling into the cluster center at a relative velocity of 2800 km s −1 , a speed constrained by its radio morphology. The infalling subcluster is expected to have a relatively low gas content, because only a gas-poor subcluster can cause central-only disturbances as observed in such an off-axis merger.

show abstract

Narrow head-tail radio galaxies at very high resolution

Cited by 22 publications

References 59 publications

The Planck clusters in the LOFAR sky. I. LoTSS-DR2: new detections and sample overview

The Planck clusters in the LOFAR sky. I. LoTSS-DR2: new detections and sample overview

Simulated Interactions between Radio Galaxies and Cluster Shocks. II. Jet Axes Orthogonal to Shock Normals

The Merger Dynamics of the Galaxy Cluster Abell 1775: New Insights from Chandra and XMM-Newton for a Cluster Simultaneously Hosting a WAT and a NAT Radio Sources

Contact Info

Product

Resources

About