scholarly journals Weak-lensing mass calibration of the Sunyaev–Zel’dovich effect using APEX-SZ galaxy clusters

2018 ◽  
Vol 488 (2) ◽  
pp. 1728-1759 ◽  
Author(s):  
A Nagarajan ◽  
F Pacaud ◽  
M Sommer ◽  
M Klein ◽  
K Basu ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Accurate Determination ◽  
Sample Selection ◽  
Weak Lensing ◽  
Scaling Relations ◽  
Precision Data ◽  
X Ray ◽  
Cluster Mass ◽  
Direct Observations ◽  
Sunyaev Zel'dovich Effect

ABSTRACT The use of galaxy clusters as precision cosmological probes relies on an accurate determination of their masses. However, inferring the relationship between cluster mass and observables from direct observations is difficult and prone to sample selection biases. In this work, we use weak lensing as the best possible proxy for cluster mass to calibrate the Sunyaev–Zel’dovich (SZ) effect measurements from the APEX-SZ experiment. For a well-defined (ROSAT) X-ray complete cluster sample, we calibrate the integrated Comptonization parameter, YSZ, to the weak-lensing derived total cluster mass, M500. We employ a novel Bayesian approach to account for the selection effects by jointly fitting both the SZ Comptonization, YSZ–M500, and the X-ray luminosity, Lx–M500, scaling relations. We also account for a possible correlation between the intrinsic (lognormal) scatter of Lx and YSZ at fixed mass. We find the corresponding correlation coefficient to be $r= 0.47_{-0.35}^{+0.24}$, and at the current precision level our constraints on the scaling relations are consistent with previous works. For our APEX-SZ sample, we find that ignoring the covariance between the SZ and X-ray observables biases the normalization of the YSZ–M500 scaling high by 1–2σ and the slope low by ∼1σ, even when the SZ effect plays no role in the sample selection. We conclude that for higher precision data and larger cluster samples, as anticipated from on-going and near-future cluster cosmology experiments, similar biases (due to intrinsic covariances of cluster observables) in the scaling relations will dominate the cosmological error budget if not accounted for correctly.

scholarly journals A general framework to test gravity using galaxy clusters III: Observable-mass scaling relations in f(R) gravity

2021 ◽  
Author(s):  
Myles A Mitchell ◽  
Christian Arnold ◽  
Baojiu Li
Keyword(s):  
Galaxy Formation ◽  
General Framework ◽  
Accurate Determination ◽  
Galaxy Cluster ◽  
Scaling Relations ◽  
Gas Temperature ◽  
Temperature Relation ◽  
X Ray ◽  
Mass Scaling ◽  
Cluster Mass

Abstract We test two methods, including one that is newly proposed in this work, for correcting for the effects of chameleon f(R) gravity on the scaling relations between the galaxy cluster mass and four observable proxies. Using the first suite of cosmological simulations that simultaneously incorporate both full physics of galaxy formation and Hu-Sawicki f(R) gravity, we find that these rescaling methods work with a very high accuracy for the gas temperature, the Compton Y-parameter of the Sunyaev-Zel’dovich (SZ) effect and the X-ray analogue of the Y-parameter. This allows the scaling relations in f(R) gravity to be mapped to their ΛCDM counterparts to within a few percent. We confirm that a simple analytical tanh formula for the ratio between the dynamical and true masses of haloes in chameleon f(R) gravity, proposed and calibrated using dark-matter-only simulations in a previous work, works equally well for haloes identified in simulations with two very different – full-physics and non-radiative – baryonic models. The mappings of scaling relations can be computed using this tanh formula, which depends on the halo mass, redshift and size of the background scalar field, also at a very good accuracy. Our results can be used for accurate determination of the cluster mass using SZ and X-ray observables, and will form part of a general framework for unbiased and self-consistent tests of gravity using data from present and upcoming galaxy cluster surveys. We also propose an alternative test of gravity, using the YX-temperature relation, which does not involve mass calibration.

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.

The AGN dependence on cluster mass

2018 ◽  
Vol 14 (S342) ◽  
pp. 145-148
Author(s):  
Elias Koulouridis ◽  
Keyword(s):  
Galaxy Clusters ◽  
High Velocity ◽  
High Redshift ◽  
High Mass ◽  
X Ray ◽  
Cluster Galaxies ◽  
Cluster Mass ◽  
Bona Fide ◽  
Low Mass ◽  
Velocity Dispersions

AbstractWe present the results of a study of the AGN density in a homogeneous and well studied sample of 167 bona-fide X-ray galaxy clusters (0.1<z<0.5). Our aim is to study the AGN activity in 167 XXL X-ray galaxy clusters as a function of the cluster mass and the location of the AGN in the cluster. We report a significant AGN excess in our low-mass cluster sub-sample between 0.5r500 and 2r500. In contrast, the high-mass sub-sample presents no AGN excess. The AGN excess in poor clusters indicates AGN triggering, supporting previous studies that reported enhanced galaxy merging in the cluster outskirts. This effect is probably prevented by high velocity dispersions in high-mass clusters. Comparing also with previous studies of massive or high-redshift clusters, we conclude that the AGN fraction in cluster galaxies anti-correlates strongly with cluster mass.

scholarly journals X-ray calibration of Sunyaev-Zel’dovich scaling relations with the ACCEPT catalogue of galaxy clusters observed by Chandra

2011 ◽  
Vol 418 (2) ◽  
pp. 1089-1101 ◽  
Author(s):  
B. Comis ◽  
M. De Petris ◽  
A. Conte ◽  
L. Lamagna ◽  
S. De Gregori
Keyword(s):  
Galaxy Clusters ◽  
Scaling Relations ◽  
X Ray

scholarly journals Scaling Relations from Sunyaev‐Zel’dovich Effect andChandraX‐Ray Measurements of High‐Redshift Galaxy Clusters

2008 ◽  
Vol 675 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Massimiliano Bonamente ◽  
Marshall Joy ◽  
Samuel J. LaRoque ◽  
John E. Carlstrom ◽  
Daisuke Nagai ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
High Redshift ◽  
Scaling Relations ◽  
Redshift Galaxy ◽  
Sunyaev Zel'dovich Effect

scholarly journals Probing cosmic isotropy with a new X-ray galaxy cluster sample through the LX–T scaling relation

2020 ◽  
Vol 636 ◽  
pp. A15 ◽  
Author(s):  
K. Migkas ◽  
G. Schellenberger ◽  
T. H. Reiprich ◽  
F. Pacaud ◽  
M. E. Ramos-Ceja ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Statistical Significance ◽  
Cosmological Parameters ◽  
Galaxy Cluster ◽  
Temperature Measurements ◽  
Joint Analysis ◽  
Scaling Relations ◽  
Exact Nature ◽  
X Rays ◽  
X Ray

The isotropy of the late Universe and consequently of the X-ray galaxy cluster scaling relations is an assumption greatly used in astronomy. However, within the last decade, many studies have reported deviations from isotropy when using various cosmological probes; a definitive conclusion has yet to be made. New, effective and independent methods to robustly test the cosmic isotropy are of crucial importance. In this work, we use such a method. Specifically, we investigate the directional behavior of the X-ray luminosity-temperature (LX–T) relation of galaxy clusters. A tight correlation is known to exist between the luminosity and temperature of the X-ray-emitting intracluster medium of galaxy clusters. While the measured luminosity depends on the underlying cosmology through the luminosity distance DL, the temperature can be determined without any cosmological assumptions. By exploiting this property and the homogeneous sky coverage of X-ray galaxy cluster samples, one can effectively test the isotropy of cosmological parameters over the full extragalactic sky, which is perfectly mirrored in the behavior of the normalization A of the LX–T relation. To do so, we used 313 homogeneously selected X-ray galaxy clusters from the Meta-Catalogue of X-ray detected Clusters of galaxies. We thoroughly performed additional cleaning in the measured parameters and obtain core-excised temperature measurements for all of the 313 clusters. The behavior of the LX–T relation heavily depends on the direction of the sky, which is consistent with previous studies. Strong anisotropies are detected at a ≳4σ confidence level toward the Galactic coordinates (l, b) ∼ (280°, − 20°), which is roughly consistent with the results of other probes, such as Supernovae Ia. Several effects that could potentially explain these strong anisotropies were examined. Such effects are, for example, the X-ray absorption treatment, the effect of galaxy groups and low redshift clusters, core metallicities, and apparent correlations with other cluster properties, but none is able to explain the obtained results. Analyzing 105 bootstrap realizations confirms the large statistical significance of the anisotropic behavior of this sky region. Interestingly, the two cluster samples previously used in the literature for this test appear to have a similar behavior throughout the sky, while being fully independent of each other and of our sample. Combining all three samples results in 842 different galaxy clusters with luminosity and temperature measurements. Performing a joint analysis, the final anisotropy is further intensified (∼5σ), toward (l, b) ∼ (303°, − 27°), which is in very good agreement with other cosmological probes. The maximum variation of DL seems to be ∼16 ± 3% for different regions in the sky. This result demonstrates that X-ray studies that assume perfect isotropy in the properties of galaxy clusters and their scaling relations can produce strongly biased results whether the underlying reason is cosmological or related to X-rays. The identification of the exact nature of these anisotropies is therefore crucial for any statistical cluster physics or cosmology study.

scholarly journals LOW X-RAY LUMINOSITY GALAXY CLUSTERS: MAIN GOALS, SAMPLE SELECTION, PHOTOMETRIC AND SPECTROSCOPIC OBSERVATIONS

2016 ◽  
Vol 151 (6) ◽  
pp. 151
Author(s):  
José Luis Nilo Castellón ◽  
M. Victoria Alonso ◽  
Diego García Lambas ◽  
Carlos Valotto ◽  
Ana Laura O’ Mill ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Sample Selection ◽  
X Ray ◽  
Spectroscopic Observations ◽  
Photometric And Spectroscopic Observations ◽  
Low X

scholarly journals The X-ray properties of weak-lensing-selected galaxy clusters

2015 ◽  
Vol 447 (4) ◽  
pp. 3044-3059 ◽  
Author(s):  
P. A. Giles ◽  
B. J. Maughan ◽  
T. Hamana ◽  
S. Miyazaki ◽  
M. Birkinshaw ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Weak Lensing ◽  
X Ray
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