scholarly journals Turbulent pressure support and hydrostatic mass bias in the intracluster medium

2020 ◽  
Vol 495 (1) ◽  
pp. 864-885 ◽  
Author(s):  
M Angelinelli ◽  
F Vazza ◽  
C Giocoli ◽  
S Ettori ◽  
T W Jones ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Pressure Support ◽  
Complex Dynamics ◽  
Polynomial Function ◽  
Intracluster Medium ◽  
Simple Correlation ◽  
Thermal Pressure ◽  
X Ray ◽  
Turbulent Pressure ◽  
Radial Behaviour

ABSTRACT The degree of turbulent pressure support by residual gas motions in galaxy clusters is not well known. Mass modelling of combined X-ray and Sunyaev–Zel’dovich observations provides an estimate of turbulent pressure support in the outer regions of several galaxy clusters. Here, we test two different filtering techniques to disentangle bulk from turbulent motions in non-radiative high-resolution cosmological simulations of galaxy clusters using the cosmological hydrocode enzo. We find that the radial behaviour of the ratio of non-thermal pressure to total gas pressure as a function of cluster-centric distance can be described by a simple polynomial function. The typical non-thermal pressure support in the centre of clusters is ∼5 per cent, increasing to ∼15 per cent in the outskirts, in line with the pressure excess found in recent X-ray observations. While the complex dynamics of the intracluster medium makes it impossible to reconstruct a simple correlation between turbulent motions and hydrostatic bias, we find that a relation between them can be established using the median properties of a sample of objects. Moreover, we estimate the contribution of radial accelerations to the non-thermal pressure support and conclude that it decreases moving outwards from 40 per cent (in the core) to 15 per cent (in the cluster’s outskirts). Adding this contribution to one provided by turbulence, we show that it might account for the entire observed hydrostatic bias in the innermost regions of the clusters, and for less than 80 per cent of it at r > 0.8 r200,m.

scholarly journals Cluster Physics & Evolution

2015 ◽  
Vol 11 (A29B) ◽  
pp. 70-78
Author(s):  
Daisuke Nagai ◽  
Monique Arnaud ◽  
Sarthak Dasadia ◽  
Michael McDonald ◽  
Ikuyuki Mitsuishi ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Statistical Power ◽  
Scaling Relations ◽  
Intracluster Medium ◽  
Physical Processes ◽  
X Ray ◽  
Cosmological Constraints ◽  
Recent Advances

AbstractRecent advances in X-ray and microwave observations have provided unprecedented insights into the structure and evolution of the hot X-ray emitting plasma from their cores to the virialization region in outskirts of galaxy clusters. Recent Sunyaev-Zel'dovich (SZ) surveys (ACT, Planck, SPT) have provided new cluster catalogs, significantly expanding coverage of the mass-redshift plane, whileChandraandXMM-NewtonX-ray follow-up programs have improved our understanding of cluster physics and evolution as well as the surveys themselves. However, the current cluster-based cosmological constraints are still limited by uncertainties in cluster astrophysics. In order to exploit the statistical power of the current and upcoming X-ray and microwave cluster surveys, it is critical to improve our understanding of the structure and evolution of the hot X-ray emitting intracluster medium (ICM). In this session, we discussed recent advances in observations and simulations of galaxy clusters, with highlights on (i) the evolution of ICM profiles and scaling relations, (ii) physical processes operating in the outskirts of galaxy clusters, and (iii) impact of mergers on the ICM structure in groups and clusters.

scholarly journals Precessing AGN jets, bubbles and cooling flows

2010 ◽  
Vol 6 (S275) ◽  
Author(s):  
D. Falceta-Gonçalves ◽  
A. Caproni ◽  
Z. Abraham ◽  
E. M. de Gouveia Dal Pino ◽  
D. M. Teixeira
Keyword(s):  
Galaxy Clusters ◽  
Flow Problem ◽  
X Rays ◽  
Intracluster Medium ◽  
X Ray ◽  
Cooling Flows ◽  
Cooling Flow ◽  
Central Regions ◽  
Multiple Bubbles ◽  
Hydrodynamical Simulations

AbstractSeveral galaxy clusters are known to present multiple and misaligned pairs of cavities seen in X-rays, as well as twisted kiloparsec-scale jets at radio wavelengths. It suggests that the AGN precessing jets play a role in the formation of the misaligned bubbles. Also, X-ray spectra reveal that typically these systems are also able to supress cooling flows, predicted theoretically. The absence of cooling flows in galaxy clusters has been a mistery for many years since numerical simulations and analytical studies suggest that AGN jets are highly energetic, but are unable to redistribute it at all directions. We performed 3D hydrodynamical simulations of the interaction between a precessing AGN jet and the warm intracluster medium plasma, in which dynamics is coupled to a NFW dark matter gravitational potential. Radiative cooling has been taken into account and the cooling flow problem was studied. We found that precession is responsible for multiple pairs of bubbles, as observed. The misaligned bubbles rise up to scales of tens of kiloparsecs, where the thermal energy released by the jets are redistributed. After ~150 Myrs, the temperature of the gas within the cavities is kept of order of ~107 K, while the denser plasma of the intracluster medium at the central regions reaches T ~ 105 K. The existence of multiple bubbles, at diferent directions, results in an integrated temperature along the line of sight much larger than the simulations of non-precessing jets. This result is in agreement with the observations. The simulations reveal that the cooling flows cessed ~50–70 Myr after the AGN jets are started.

scholarly journals Characterizing galaxy clusters by their gravitational potential: Systematics of cluster potential reconstruction

2020 ◽  
Vol 644 ◽  
pp. A126
Author(s):  
C. Tchernin ◽  
E. T. Lau ◽  
S. Stapelberg ◽  
D. Hug ◽  
M. Bartelmann
Keyword(s):  
Galaxy Clusters ◽  
Gravitational Potential ◽  
Pressure Support ◽  
Good Alternative ◽  
Mass Measurements ◽  
Cosmological Simulations ◽  
Promising Alternative ◽  
X Ray ◽  
Mass Bias ◽  
Millimeter Wavelengths

Context. Biases in mass measurements of galaxy clusters are one of the major limiting systematics in constraining cosmology with clusters. Aims. We aim to demonstrate that the systematics associated with cluster gravitational potentials are smaller than the hydrostatic mass bias and that cluster potentials could therefore be a good alternative to cluster masses in cosmological studies. Methods. Using cosmological simulations of galaxy clusters, we compute the biases in the hydrostatic mass (HE mass) and those in the gravitational potential, reconstructed from measurements at X-ray and millimeter wavelengths. In particular, we investigate the effects of the presence of substructures and of nonthermal pressure support on both the HE mass and the reconstructed potential. Results. We find that the bias in the reconstructed potential (6%) is less than that of the HE mass (13%) and that the scatter in the reconstructed potential decreases by ∼35% with respect to that in the HE mass. Conclusions. This study shows that characterizing galaxy clusters by their gravitational potential is a promising alternative to using cluster masses in cluster cosmology.

scholarly journals JOINT ANALYSIS OF X-RAY AND SUNYAEV-ZEL'DOVICH OBSERVATIONS OF GALAXY CLUSTERS USING AN ANALYTIC MODEL OF THE INTRACLUSTER MEDIUM

2012 ◽  
Vol 748 (2) ◽  
pp. 113 ◽  
Author(s):  
Nicole Hasler ◽  
Esra Bulbul ◽  
Massimiliano Bonamente ◽  
John E. Carlstrom ◽  
Thomas L. Culverhouse ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Joint Analysis ◽  
Analytic Model ◽  
Intracluster Medium ◽  
X Ray

scholarly journals The turbulent pressure support in galaxy clusters revisited

2018 ◽  
Vol 481 (1) ◽  
pp. L120-L124 ◽  
Author(s):  
F Vazza ◽  
M Angelinelli ◽  
T W Jones ◽  
D Eckert ◽  
M Brüggen ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Pressure Support ◽  
Turbulent Pressure

scholarly journals Turbulent pressure support in the outer parts of galaxy clusters

2011 ◽  
Vol 419 (1) ◽  
pp. L29-L33 ◽  
Author(s):  
Ian J. Parrish ◽  
Michael McCourt ◽  
Eliot Quataert ◽  
Prateek Sharma
Keyword(s):  
Galaxy Clusters ◽  
Pressure Support ◽  
Turbulent Pressure

scholarly journals Imprints of mass accretion history on the shape of the intracluster medium and the TX–M relation

2019 ◽  
Vol 490 (2) ◽  
pp. 2380-2389 ◽  
Author(s):  
Huanqing Chen ◽  
Camille Avestruz ◽  
Andrey V Kravtsov ◽  
Erwin T Lau ◽  
Daisuke Nagai
Keyword(s):  
Galaxy Clusters ◽  
Bimodal Distribution ◽  
Characteristic Time Scale ◽  
Intracluster Medium ◽  
X Ray ◽  
Mass Scaling ◽  
Systematic Uncertainties ◽  
The Galaxy ◽  
Statistical Sample ◽  
The Impact

ABSTRACT We use a statistical sample of galaxy clusters from a large cosmological N-body + hydrodynamics simulation to examine the relation between morphology, or shape, of the X-ray emitting intracluster medium (ICM) and the mass accretion history of the galaxy clusters. We find that the mass accretion rate (MAR) of a cluster is correlated with the ellipticity of the ICM. The correlation is largely driven by material accreted in the last ∼4.5 Gyr, indicating a characteristic time-scale for relaxation of cluster gas. Furthermore, we find that the ellipticity of the outer regions (R ∼ R500c) of the ICM is correlated with the overall MAR of clusters, while ellipticity of the inner regions (≲0.5 R500c) is sensitive to recent major mergers with mass ratios of ≥1:3. Finally, we examine the impact of variations in cluster mass accretion history on the X-ray observable–mass scaling relations. We show that there is a continuous anticorrelation between the residuals in the TX–M relation and cluster MARs, within which merging and relaxed clusters occupy extremes of the distribution rather than form two peaks in a bimodal distribution, as was often assumed previously. Our results indicate that the systematic uncertainties in the X-ray observable–mass relations can be mitigated by using the information encoded in the apparent ICM ellipticity.

scholarly journals Deriving the Hubble constant using Planck and XMM-Newton observations of galaxy clusters

2019 ◽  
Vol 621 ◽  
pp. A34 ◽  
Author(s):  
Arpine Kozmanyan ◽  
Hervé Bourdin ◽  
Pasquale Mazzotta ◽  
Elena Rasia ◽  
Mauro Sereno
Keyword(s):  
Observational Data ◽  
Galaxy Clusters ◽  
Bayesian Approach ◽  
Hubble Constant ◽  
Intracluster Medium ◽  
X Ray ◽  
Spatially Resolved ◽  
Measurement Uncertainties ◽  
Hydrodynamical Simulations ◽  
Massive Clusters

The possibility of determining the value of the Hubble constant using observations of galaxy clusters in X-ray and microwave wavelengths through the Sunyaev Zel’dovich (SZ) effect has long been known. Previous measurements have been plagued by relatively large errors in the observational data and severe biases induced, for example, by cluster triaxiality and clumpiness. The advent of Planck allows us to map the Compton parameter y, that is, the amplitude of the SZ effect, with unprecedented accuracy at intermediate cluster-centric radii, which in turn allows performing a detailed spatially resolved comparison with X-ray measurements. Given such higher quality observational data, we developed a Bayesian approach that combines informed priors on the physics of the intracluster medium obtained from hydrodynamical simulations of massive clusters with measurement uncertainties. We applied our method to a sample of 61 galaxy clusters with redshifts up to z <  0.5 observed with Planck and XMM-Newton and find H0 = 67 ± 3 km s−1 Mpc−1.

scholarly journals Non-thermal pressure support in X-COP galaxy clusters

2019 ◽  
Vol 621 ◽  
pp. A40 ◽  
Author(s):  
D. Eckert ◽  
V. Ghirardini ◽  
S. Ettori ◽  
E. Rasia ◽  
V. Biffi ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Pressure Support ◽  
Energy Content ◽  
Microwave Background ◽  
Thermal Pressure ◽  
High Bias ◽  
Massive Halos ◽  
Hydrodynamical Simulations ◽  
Mass Dependent ◽  
Gas Fractions

Galaxy clusters are the endpoints of structure formation and are continuously growing through the merging and accretion of smaller structures. Numerical simulations predict that a fraction of their energy content is not yet thermalized, mainly in the form of kinetic motions (turbulence, bulk motions). Measuring the level of non-thermal pressure support is necessary to understand the processes leading to the virialization of the gas within the potential well of the main halo and to calibrate the biases in hydrostatic mass estimates. We present high-quality measurements of hydrostatic masses and intracluster gas fraction out to the virial radius for a sample of 13 nearby clusters with available XMM-Newton and Planck data. We compare our hydrostatic gas fractions with the expected universal gas fraction to constrain the level of non-thermal pressure support. We find that hydrostatic masses require little correction and infer a median non-thermal pressure fraction of ∼6% and ∼10% at R500 and R200, respectively. Our values are lower than the expectations of hydrodynamical simulations, possibly implying a faster thermalization of the gas. If instead we use the mass calibration adopted by the Planck team, we find that the gas fraction of massive local systems implies a mass bias 1 − b = 0.85 ± 0.05 for Sunyaev–Zeldovich-derived masses, with some evidence for a mass-dependent bias. Conversely, the high bias required to match Planck cosmic microwave background and cluster count cosmology is excluded by the data at high significance, unless the most massive halos are missing a substantial fraction of their baryons.

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