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 Dynamical state for 964 galaxy clusters from Chandra X-ray images

2020 ◽  
Vol 497 (4) ◽  
pp. 5485-5497
Author(s):  
Z S Yuan ◽  
J L Han
Keyword(s):  
Galaxy Clusters ◽  
Concentration Index ◽  
Bimodal Distribution ◽  
Asymmetry Factor ◽  
Power Ratio ◽  
X Ray ◽  
Dynamical State ◽  
Adaptive Parameters ◽  
Centroid Shift ◽  
Dynamical Parameters

ABSTRACT The dynamical state of galaxy clusters describes if clusters are relaxed dynamically or in a merging process of subclusters. Using archival images from the Chandra X-ray Observatory, we derive a set of parameters to describe the dynamical state for 964 galaxy clusters. Three widely used indicators for dynamical state, the concentration index c, the centroid shift ω, and the power ratio P3/P0 are calculated in the circular central region with a radius of 500 kpc. We also derive two adaptive parameters, the profile parameter κ and the asymmetry factor α, in the best fitted elliptical region. The morphology index δ is then defined by combining these two adaptive parameters, which indicates the dynamical state of galaxy clusters and has good correlations to the concentration index c, the centroid shift ω, the power ratio P3/P0, and the optical relaxation factor Γ. For a large sample of clusters, the dynamical parameters are continuously distributed from the disturbed to relaxed states with a peak in the between, rather than the bimodal distribution for the two states. We find that the newly derived morphology index δ works for the similar fundamental plane between the radio power, cluster mass, and the dynamical state for clusters with diffuse radio giant-haloes and mini-haloes. The offset between masses estimated from the Sunyaev–Zeld́ovich effect and X-ray images depends on dynamical parameters. All dynamical parameters for galaxy clusters derived from the Chandra archival images are available on http://zmtt.bao.ac.cn/galaxy_clusters/dyXimages/.

scholarly journals A joint SZ–X-ray–optical analysis of the dynamical state of 288 massive galaxy clusters

2020 ◽  
Vol 495 (1) ◽  
pp. 705-725 ◽  
Author(s):  
A Zenteno ◽  
D Hernández-Lang ◽  
M Klein ◽  
C Vergara Cervantes ◽  
D L Hollowood ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
High Redshift ◽  
Peak Position ◽  
Cluster Galaxy ◽  
X Ray ◽  
Dynamical State ◽  
Dark Energy Survey ◽  
The Galaxy ◽  
Merger Rate ◽  
Galaxy Population

ABSTRACT We use imaging from the first three years of the Dark Energy Survey to characterize the dynamical state of 288 galaxy clusters at 0.1 ≲ z ≲ 0.9 detected in the South Pole Telescope (SPT) Sunyaev–Zeldovich (SZ) effect survey (SPT-SZ). We examine spatial offsets between the position of the brightest cluster galaxy (BCG) and the centre of the gas distribution as traced by the SPT-SZ centroid and by the X-ray centroid/peak position from Chandra and XMM data. We show that the radial distribution of offsets provides no evidence that SPT SZ-selected cluster samples include a higher fraction of mergers than X-ray-selected cluster samples. We use the offsets to classify the dynamical state of the clusters, selecting the 43 most disturbed clusters, with half of those at z ≳ 0.5, a region seldom explored previously. We find that Schechter function fits to the galaxy population in disturbed clusters and relaxed clusters differ at z > 0.55 but not at lower redshifts. Disturbed clusters at z > 0.55 have steeper faint-end slopes and brighter characteristic magnitudes. Within the same redshift range, we find that the BCGs in relaxed clusters tend to be brighter than the BCGs in disturbed samples, while in agreement in the lower redshift bin. Possible explanations includes a higher merger rate, and a more efficient dynamical friction at high redshift. The red-sequence population is less affected by the cluster dynamical state than the general galaxy population.

scholarly journals The XXL Survey

2019 ◽  
Vol 632 ◽  
pp. A54 ◽  
Author(s):  
Mauro Sereno ◽  
Stefano Ettori ◽  
Dominique Eckert ◽  
Paul Giles ◽  
Ben J. Maughan ◽  
...  
Keyword(s):  
Scaling Relations ◽  
Cluster Property ◽  
X Ray ◽  
Radiative Processes ◽  
Dynamical State ◽  
Mass Temperature ◽  
Observational Uncertainty ◽  
History Of ◽  
Cluster Properties ◽  
Positive Correlations

Context. Scaling relations between cluster properties embody the formation and evolution of cosmic structure. Intrinsic scatters and correlations between X-ray properties are determined from merger history, baryonic processes, and dynamical state. Aims. We look for an unbiased measurement of the scatter covariance matrix among the three main X-ray observable quantities attainable in large X-ray surveys: temperature, luminosity, and gas mass. This also gives us the cluster property with the lowest conditional intrinsic scatter at fixed mass. Methods. Intrinsic scatters and correlations can be measured under the assumption that the observable properties of the intra-cluster medium hosted in clusters are log-normally distributed around power-law scaling relations. The proposed method is self-consistent, based on minimal assumptions, and requires neither external calibration by weak lensing, or dynamical or hydrostatic masses, nor the knowledge of the mass completeness. Results. We analysed the 100 brightest clusters detected in the XXL Survey and their X-ray properties measured within a fixed radius of 300 kpc. The gas mass is the less scattered proxy (∼8%). The temperature (∼20%) is intrinsically less scattered than the luminosity (∼30%), but it is measured with a larger observational uncertainty. We found some evidence that gas mass, temperature, and luminosity are positively correlated. Time evolutions are in agreement with the self-similar scenario, but the luminosity–temperature and the gas mass–temperature relations are steeper. Conclusion. Positive correlations between X-ray properties can be determined by the dynamical state and the merger history of the halos. The slopes of the scaling relations are affected by radiative processes.

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 High redshift X-ray galaxy clusters

2007 ◽  
Vol 472 (3) ◽  
pp. 739-748 ◽  
Author(s):  
M. Branchesi ◽  
I. M. Gioia ◽  
C. Fanti ◽  
R. Fanti
Keyword(s):  
Galaxy Clusters ◽  
High Redshift ◽  
X Ray

scholarly journals The role of AGN activity in the building up of the BCG at z ∼ 1.6

2019 ◽  
Vol 15 (S356) ◽  
pp. 280-284
Author(s):  
Angela Bongiorno ◽  
Andrea Travascio
Keyword(s):  
Galaxy Cluster ◽  
Cluster Galaxy ◽  
X Ray ◽  
Groups Of Galaxies ◽  
Star Forming ◽  
The Core ◽  
The Galaxy ◽  
Multi Wavelength

AbstractXDCPJ0044.0-2033 is one of the most massive galaxy cluster at z ∼1.6, for which a wealth of multi-wavelength photometric and spectroscopic data have been collected during the last years. I have reported on the properties of the galaxy members in the very central region (∼ 70kpc × 70kpc) of the cluster, derived through deep HST photometry, SINFONI and KMOS IFU spectroscopy, together with Chandra X-ray, ALMA and JVLA radio data.In the core of the cluster, we have identified two groups of galaxies (Complex A and Complex B), seven of them confirmed to be cluster members, with signatures of ongoing merging. These galaxies show perturbed morphologies and, three of them show signs of AGN activity. In particular, two of them, located at the center of each complex, have been found to host luminous, obscured and highly accreting AGN (λ = 0.4−0.6) exhibiting broad Hα line. Moreover, a third optically obscured type-2 AGN, has been discovered through BPT diagram in Complex A. The AGN at the center of Complex B is detected in X-ray while the other two, and their companions, are spatially related to radio emission. The three AGN provide one of the closest AGN triple at z > 1 revealed so far with a minimum (maximum) projected distance of 10 kpc (40 kpc). The discovery of multiple AGN activity in a highly star-forming region associated to the crowded core of a galaxy cluster at z ∼ 1.6, suggests that these processes have a key role in shaping the nascent Brightest Cluster Galaxy, observed at the center of local clusters. According to our data, all galaxies in the core of XDCPJ0044.0-2033 could form a BCG of M* ∼ 1012Mȯ hosting a BH of 2 × 108−109Mȯ, in a time scale of the order of 2.5 Gyrs.

scholarly journals ON THE ORIGIN OF COOL CORE GALAXY CLUSTERS: COMPARING X-RAY OBSERVATIONS WITH NUMERICAL SIMULATIONS

2009 ◽  
Vol 697 (2) ◽  
pp. 1597-1620 ◽  
Author(s):  
Jason W. Henning ◽  
Brennan Gantner ◽  
Jack O. Burns ◽  
Eric J. Hallman
Keyword(s):  
Numerical Simulations ◽  
Galaxy Clusters ◽  
X Ray

scholarly journals X-ray mapping the outer regions of galaxy clusters at z = 0.23 and 0.45

2014 ◽  
Vol 439 (2) ◽  
pp. 1796-1806 ◽  
Author(s):  
Q. Daniel Wang ◽  
Stephen Walker
Keyword(s):  
Galaxy Clusters ◽  
X Ray

scholarly journals Anisotropy of the galaxy cluster X-ray luminosity–temperature relation

2018 ◽  
Vol 611 ◽  
pp. A50 ◽  
Author(s):  
Konstantinos Migkas ◽  
Thomas H. Reiprich
Keyword(s):  
Galaxy Clusters ◽  
Statistical Significance ◽  
Cosmological Parameters ◽  
Galaxy Cluster ◽  
Luminosity Distance ◽  
Temperature Relation ◽  
X Ray ◽  
Two Samples ◽  
The Galaxy ◽  
Group A

We introduce a new test to study the cosmological principle with galaxy clusters. Galaxy clusters exhibit a tight correlation between the luminosity and temperature of the X-ray-emitting intracluster medium. While the luminosity measurement depends on cosmological parameters through the luminosity distance, the temperature determination is cosmology-independent. We exploit this property to test the isotropy of the luminosity distance over the full extragalactic sky, through the normalization a of the LX–T scaling relation and the cosmological parameters Ωm and H0. To this end, we use two almost independent galaxy cluster samples: the ASCA Cluster Catalog (ACC) and the XMM Cluster Survey (XCS-DR1). Interestingly enough, these two samples appear to have the same pattern for a with respect to the Galactic longitude. More specifically, we identify one sky region within l ~ (−15°, 90°) (Group A) that shares very different best-fit values for the normalization of the LX–T relation for both ACC and XCS-DR1 samples. We use the Bootstrap and Jackknife methods to assess the statistical significance of these results. We find the deviation of Group A, compared to the rest of the sky in terms of a, to be ~2.7σ for ACC and ~3.1σ for XCS-DR1. This tension is not significantly relieved after excluding possible outliers and is not attributed to different redshift (z), temperature (T), or distributions of observable uncertainties. Moreover, a redshift conversion to the cosmic microwave background (CMB) frame does not have an important impact on our results. Using also the HIFLUGCS sample, we show that a possible excess of cool-core clusters in this region, is not able to explain the obtained deviations. Furthermore, we tested for a dependence of the results on supercluster environment, where the fraction of disturbed clusters might be enhanced, possibly affecting the LX–T relation. We indeed find a trend in the XCS-DR1 sample for supercluster members to be underluminous compared to field clusters. However, the fraction of supercluster members is similar in the different sky regions, so this cannot explain the observed differences, either. Constraining Ωm and H0 via the redshift evolution of LX–T and the luminosity distance via the flux–luminosity conversion, we obtain approximately the same deviation amplitudes as for a. It is interesting that the general observed behavior of Ωm for the sky regions that coincide with the CMB dipole is similar to what was found with other cosmological probes such as supernovae Ia. The reason for this behavior remains to be identified.

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