scholarly journals Probing the dynamical state, baryon content, and multiphase nature of galaxy clusters with bright background QSOs

2018 ◽  
Vol 481 (3) ◽  
pp. 4111-4122 ◽  
Author(s):  
Chong Ge ◽  
Q Daniel Wang ◽  
Joseph N Burchett ◽  
Todd M Tripp ◽  
Ming Sun ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Dynamical State ◽  
State Baryon

Mass distribution and Dynamical State of Galaxy Clusters in the LZLS Sample

2006 ◽  
Vol 20 ◽  
pp. 269-270 ◽  
Author(s):  
L.E. Campusano ◽  
E.S. Cypriano ◽  
L. Jr. Sodré ◽  
J.-P. Kneib
Keyword(s):  
Galaxy Clusters ◽  
Mass Distribution ◽  
Dynamical State

scholarly journals The Three Hundred project: shapes and radial alignment of satellite, infalling, and backsplash galaxies

2020 ◽  
Vol 495 (3) ◽  
pp. 3002-3013 ◽  
Author(s):  
Alexander Knebe ◽  
Matías Gámez-Marín ◽  
Frazer R Pearce ◽  
Weiguang Cui ◽  
Kai Hoffmann ◽  
...  
Keyword(s):  
Dark Matter ◽  
Galaxy Clusters ◽  
Galaxy Cluster ◽  
Cluster Radius ◽  
Dynamical State ◽  
The Galaxy ◽  
Radial Orbit ◽  
Galaxy Halo ◽  
Satellite Galaxies

ABSTRACT Using 324 numerically modelled galaxy clusters, we investigate the radial and galaxy–halo alignment of dark matter subhaloes and satellite galaxies orbiting within and around them. We find that radial alignment depends on distance to the centre of the galaxy cluster but appears independent of the dynamical state of the central host cluster. Furthermore, we cannot find a relation between radial alignment of the halo or galaxy shape with its own mass. We report that backsplash galaxies, i.e. objects that have already passed through the cluster radius but are now located in the outskirts, show a stronger radial alignment than infalling objects. We further find that there exists a population of well radially aligned objects passing very close to the central cluster’s centre that were found to be on highly radial orbit.

scholarly journals The dynamical state and mass–concentration relation of galaxy clusters

2012 ◽  
Vol 427 (2) ◽  
pp. 1322-1328 ◽  
Author(s):  
Aaron D. Ludlow ◽  
Julio F. Navarro ◽  
Ming Li ◽  
Raul E. Angulo ◽  
Michael Boylan-Kolchin ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Mass Concentration ◽  
Dynamical State

scholarly journals On the dynamical state of galaxy clusters: insights from cosmological simulations – II.

2016 ◽  
Vol 464 (2) ◽  
pp. 2502-2510 ◽  
Author(s):  
Weiguang Cui ◽  
Chris Power ◽  
Stefano Borgani ◽  
Alexander Knebe ◽  
Geraint F. Lewis ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Cosmological Simulations ◽  
Dynamical State

scholarly journals The role of penetrating gas streams in setting the dynamical state of galaxy clusters

2016 ◽  
Vol 461 (1) ◽  
pp. 412-432 ◽  
Author(s):  
E. Zinger ◽  
A. Dekel ◽  
Y. Birnboim ◽  
A. Kravtsov ◽  
D. Nagai
Keyword(s):  
Galaxy Clusters ◽  
Gas Streams ◽  
Dynamical State

scholarly journals Cosmic dance in the Shapley Concentration Core

2018 ◽  
Vol 620 ◽  
pp. A25
Author(s):  
G. Di Gennaro ◽  
T. Venturi ◽  
D. Dallacasa ◽  
S. Giacintucci ◽  
P. Merluzzi ◽  
...  
Keyword(s):  
Radio Emission ◽  
Galaxy Clusters ◽  
Radio Galaxies ◽  
Wide Field ◽  
Host Galaxies ◽  
Very Large Array ◽  
Cluster Complexes ◽  
Dynamical State ◽  
Sky Survey ◽  
Radio Band

Context. The Shapley Concentration (⟨z⟩ ≈ 0.048) covers several degrees in the southern hemisphere, and includes galaxy clusters in advanced evolutionary stages, groups of clusters in the very early stages of merger, fairly massive clusters with ongoing accretion activity, and smaller groups located in filaments in the regions between the main clusters. Aims. With the goal to investigate the role of cluster mergers and accretion on the radio galaxy population, we performed a multi-wavelength study of the brightest cluster galaxies (BCGs) and of the galaxies showing extended radio emission in the cluster complexes of Abell 3528 and Abell 3558. In total, our study is based on a sample of 12 galaxies. Methods. We observed the clusters with the Giant Metrewave Radio Telescope (GMRT) at 235, 325, and 610 MHz, and with the Very Large Array (VLA) at 8.46 GHz. We complemented our study with the TIFR GMRT Sky Survey (TGSS) at 150 MHz, the Sydney University Molonglo Sky Survey (SUMSS) at 843 MHz, and the Australia Telescope Compact array (ATCA) at 1380, 1400, 2380, and 4790 MHz data. Finally, optical imaging with the VLT Survey Telescope (VST) is also available for the host galaxies as well as the mid-infrared coverage with the Wide-Field Infrared Survey Explorer (WISE). Results. We found significant differences in the properties of the radio emission of the BCGs in the two cluster complexes. The BCGs in the A 3528 complex and in A 3556, which are relaxed cool-core objects, are powerful active radio galaxies. They also present hints of restarted activity. On the contrary, the BCGs in A 3558 and A 3562, which are well-known merging systems, are very faint, or quiet, in the radio band. The optical and infrared properties of the galaxies, on the other hand, are fairly similar in the two complexes, showing all passive red galaxies. Conclusions. Our study shows remarkable differences in the radio properties of the BGCs, which we relate to the different dynamical state of the host cluster. On the contrary, the lack of changes between such different environments in the optical band suggests that the dynamical state of galaxy clusters does not affect the optical counterparts of the radio galaxies, at least over the lifetime of the radio emission.

scholarly journals TheThreeHundred project: backsplash galaxies in simulations of clusters

2020 ◽  
Vol 492 (4) ◽  
pp. 6074-6085 ◽  
Author(s):  
Roan Haggar ◽  
Meghan E Gray ◽  
Frazer R Pearce ◽  
Alexander Knebe ◽  
Weiguang Cui ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Galaxy Cluster ◽  
Recent History ◽  
Cluster Galaxies ◽  
Cluster Centre ◽  
Dynamical State ◽  
History Of ◽  
First Time

ABSTRACT In the outer regions of a galaxy cluster, galaxies either may be falling into the cluster for the first time or have already passed through the cluster centre at some point in their past. To investigate these two distinct populations, we utilize TheThreeHundred project, a suite of 324 hydrodynamical resimulations of galaxy clusters. In particular, we study the ‘backsplash population’ of galaxies: those that have passed within R200 of the cluster centre at some time in their history, but are now outside of this radius. We find that, on average, over half of all galaxies between R200 and 2R200 from their host at $z$ = 0 are backsplash galaxies, but that this fraction is dependent on the dynamical state of a cluster, as dynamically relaxed clusters have a greater backsplash fraction. We also find that this population is mostly developed at recent times ($z$ ≲ 0.4), and is dependent on the recent history of a cluster. Finally, we show that the dynamical state of a given cluster, and thus the fraction of backsplash galaxies in its outskirts, can be predicted based on observational properties of the cluster.

scholarly journals The Three Hundred Project: Dynamical state of galaxy clusters and morphology from multi-wavelength synthetic maps

2021 ◽  
Author(s):  
Federico De Luca ◽  
Marco De Petris ◽  
Gustavo Yepes ◽  
Weiguang Cui ◽  
Alexander Knebe ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Continuous Distribution ◽  
Accurate Estimation ◽  
Cluster Property ◽  
Morphological Parameters ◽  
Density Peak ◽  
X Ray ◽  
Dynamical State ◽  
Multi Wavelength ◽  
Highly Correlated

Abstract We study the connection between morphology and dynamical state of the simulated galaxy clusters in z ∈ [0, 1.031] from The Three Hundred Project. We quantify cluster dynamical state using a combination of dynamical indicators from theoretical measures and compare this combined parameter, χ, with the results from morphological classifications. The dynamical state of the cluster sample shows a continuous distribution from dynamically relaxed, more abundant at lower redshift, to hybrid and disturbed. The dynamical state presents a clear dependence on the radius, with internal regions more relaxed than outskirts. The morphology from multi-wavelength mock observation of clusters in X-ray, optical, and Sunyaev-Zel’dovich (SZ) effect images, is quantified by M – a combination of six parameters for X-ray and SZ maps and the offsets between the optical position of the Brightest Central Galaxy (BCG) and the X-ray/SZ centroids. All the morphological parameters are highly correlated with each other, while they show a moderately strong correlation with the dynamical χ parameter. The X-ray or SZ peaks are less affected by the dynamical state than centroids, which results in reliable tracers of the cluster density peak. The principal source of contamination in the relaxed cluster fraction, inferred from morphological parameters, is due to dynamically hybrid clusters. Compared to individual parameters, which consider only one aspect of cluster property (e.g. only clumping or asymmetry), the combined morphological and dynamical parameters (M and χ) collect more information and provide a single and more accurate estimation of the cluster dynamical state.

scholarly journals A LOFAR study of non-merging massive galaxy clusters

2019 ◽  
Vol 622 ◽  
pp. A24 ◽  
Author(s):  
F. Savini ◽  
A. Bonafede ◽  
M. Brüggen ◽  
D. Rafferty ◽  
T. Shimwell ◽  
...  
Keyword(s):  
Particle Acceleration ◽  
Radio Emission ◽  
Galaxy Clusters ◽  
Large Scale ◽  
Low Frequency ◽  
Cosmic Ray ◽  
Dynamical State ◽  
Core Cluster ◽  
Spectrum Radio ◽  
Massive Clusters

Centrally located diffuse radio emission has been observed in both merging and non-merging galaxy clusters. Depending on their morphology and size, we distinguish between giant radio haloes, which occur predominantly in merging clusters, and mini haloes, which are found in non-merging, cool-core clusters. In recent years, cluster-scale radio emission has also been observed in clusters with no sign of major mergers, showing that our knowledge of the mechanisms that lead to particle acceleration in the intra-cluster medium (ICM) is still incomplete. Low-frequency sensitive observations are required to assess whether the emission discovered in these few cases is common in galaxy clusters or not. With this aim, we carried out a campaign of observations with the LOw Frequency ARay (LOFAR) in the frequency range 120–168 MHz of nine massive clusters selected from the Planck SZ catalogue, which had no sign of major mergers. In this paper, we discuss the results of the observations that have led to the largest cluster sample studied within the LOFAR Two-metre Sky Survey, and we present Chandra X-ray data used to investigate the dynamical state of the clusters, verifying that the clusters are currently not undergoing major mergers, and to search for traces of minor or off-axis mergers. We discover large-scale steep-spectrum emission around mini haloes in the cool-core clusters PSZ1G139.61+24 and RXJ1720.1+2638, which is not observed around the mini halo in the non-cool-core cluster A1413. We also discover a new 570 kpc-halo in the non-cool-core cluster RXCJ0142.0+2131. We derived new upper limits to the radio power for clusters in which no diffuse radio emission was found, and we discuss the implication of our results to constrain the cosmic-ray energy budget in the ICM. We conclude that radio emission in non-merging massive clusters is not common at the sensitivity level reached by our observations and that no clear connection with the cluster dynamical state is observed. Our results might indicate that the sloshing of a dense cool core could trigger particle acceleration on larger scales and generate steep-spectrum radio emission.

Sign in / Sign up

Export Citation Format

Share Document