scholarly journals Weak lensing calibration of mass bias in the REFLEX+BCS X-ray galaxy cluster catalogue

2016 ◽  
Vol 466 (3) ◽  
pp. 3663-3673 ◽  
Author(s):  
Melanie Simet ◽  
Nicholas Battaglia ◽  
Rachel Mandelbaum ◽  
Uroš Seljak
Keyword(s):  
Galaxy Cluster ◽  
Weak Lensing ◽  
X Ray ◽  
Mass Bias

scholarly journals Reconciling galaxy cluster shapes, measured by theorists versus observers

2020 ◽  
Vol 500 (2) ◽  
pp. 2627-2644
Author(s):  
David Harvey ◽  
Andrew Robertson ◽  
Sut-Ieng Tam ◽  
Mathilde Jauzac ◽  
Richard Massey ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Orientation Angle ◽  
Galaxy Cluster ◽  
Galactic Nuclei ◽  
Weak Lensing ◽  
Strongly Correlated ◽  
The Bahamas ◽  
Cluster Galaxy ◽  
Moments Of Inertia ◽  
X Ray

ABSTRACT If properly calibrated, the shapes of galaxy clusters can be used to investigate many physical processes: from feedback and quenching of star formation, to the nature of dark matter. Theorists frequently measure shapes using moments of inertia of simulated particles’. We instead create mock (optical, X-ray, strong-, and weak-lensing) observations of the 22 most massive ($\sim 10^{14.7}\, \mathrm{ M}_\odot$) relaxed clusters in the BAHAMAS simulations. We find that observable measures of shape are rounder. Even when moments of inertia are projected into 2D and evaluated at matched radius, they overestimate ellipticity by 56 per cent (compared to observable strong lensing) and 430 per cent (compared to observable weak lensing). Therefore, we propose matchable quantities and test them using observations of eight relaxed clusters from the Hubble Space Telescope (HST) and Chandra X-Ray Observatory. We also release our HST data reduction and lensing analysis software to the community. In real clusters, the ellipticity and orientation angle at all radii are strongly correlated. In simulated clusters, the ellipticity of inner (<rvir/20) regions becomes decoupled: for example, with greater misalignment of the central cluster galaxy. This may indicate overly efficient implementation of feedback from active galactic nuclei. Future exploitation of cluster shapes as a function of radii will require better understanding of core baryonic processes. Exploitation of shapes on any scale will require calibration on simulations extended all the way to mock observations.

scholarly journals Impact of Weak Lensing Mass Calibration on eROSITA Galaxy Cluster Cosmological Studies – a Forecast

2019 ◽  
Author(s):  
S Grandis ◽  
J J Mohr ◽  
J P Dietrich ◽  
S Bocquet ◽  
A Saro ◽  
...  
Keyword(s):  
Count Rate ◽  
Galaxy Cluster ◽  
Effective Area ◽  
Mass Scale ◽  
Weak Lensing ◽  
Parameter Uncertainties ◽  
X Ray ◽  
Mass Scaling ◽  
Mass Calibration ◽  
The Impact

Abstract We forecast the impact of weak lensing (WL) cluster mass calibration on the cosmological constraints from the X-ray selected galaxy cluster counts in the upcoming eROSITA survey. We employ a prototype cosmology pipeline to analyze mock cluster catalogs. Each cluster is sampled from the mass function in a fiducial cosmology and given an eROSITA count rate and redshift, where count rates are modeled using the eROSITA effective area, a typical exposure time, Poisson noise and the scatter and form of the observed X-ray luminosity– and temperature–mass–redshift relations. A subset of clusters have mock shear profiles to mimic either those from DES and HSC or from the future Euclid and LSST surveys. Using a count rate selection, we generate a baseline cluster cosmology catalog that contains 13k clusters over 14,892 deg2 of extragalactic sky. Low mass groups are excluded using raised count rate thresholds at low redshift. Forecast parameter uncertainties for ΩM, σ8 and w are 0.023 (0.016; 0.014), 0.017 (0.012; 0.010), and 0.085 (0.074; 0.071), respectively, when adopting DES+HSC WL (Euclid; LSST), while marginalizing over the sum of the neutrino masses. A degeneracy between the distance–redshift relation and the parameters of the observable–mass scaling relation limits the impact of the WL calibration on the w constraints, but with BAO measurements from DESI an improved determination of w to 0.043 becomes possible. With Planck CMB priors, ΩM (σ8) can be determined to 0.005 (0.007), and the summed neutrino mass limited to ∑mν < 0.241 eV (at 95%). If systematics on the group mass scale can be controlled, the eROSITA group and cluster sample with 43k objects and LSST WL could constrain ΩM and σ8 to 0.007 and w to 0.050.

scholarly journals The massive galaxy cluster XMMU J1230.3+1339 at z ∼ 1: colour-magnitude relation, Butcher-Oemler effect, X-ray and weak lensing mass estimates★

2011 ◽  
Vol 411 (4) ◽  
pp. 2667-2694 ◽  
Author(s):  
M. Lerchster ◽  
S. Seitz ◽  
F. Brimioulle ◽  
R. Fassbender ◽  
M. Rovilos ◽  
...  
Keyword(s):  
Galaxy Cluster ◽  
Weak Lensing ◽  
X Ray ◽  
Massive Galaxy

scholarly journals Investigating the Relationship Between the Hot Gas and the Dark Matter Components of Galaxy Clusters.

2007 ◽  
Vol 3 (S244) ◽  
pp. 374-375
Author(s):  
Leila C. Powell ◽  
Scott T. Kay ◽  
Arif Babul ◽  
Andisheh Mahdavi
Keyword(s):  
Dark Matter ◽  
Total Mass ◽  
Surface Brightness ◽  
Galaxy Cluster ◽  
Weak Lensing ◽  
X Ray ◽  
Hot Gas ◽  
Cluster Properties ◽  
The Impact ◽  
The Relationship

AbstractVarious differences in galaxy cluster properties derived from X-ray and weak lensing observations have been highlighted in the literature. One such difference is the observation of mass concentrations in lensing maps which have no X-ray counterparts (e.g. Jee, White, Ford et al. 2005). We investigate this issue by identifying substructures in maps of projected total mass (analogous to weak lensing mass reconstructions) and maps of projected X-ray surface brightness for three simulated clusters. We then compare the 2D mass substructures with both 3D subhalo data and the 2D X-ray substructures. Here we present preliminary results from the first comparison, where we have assessed the impact of projecting the data on subhalo identification.

scholarly journals XMM-Newton X-ray and HST weak gravitational lensing study of the extremely X-ray luminous galaxy cluster Cl J120958.9+495352 (z = 0.902)

2018 ◽  
Vol 610 ◽  
pp. A71 ◽  
Author(s):  
Sophia Thölken ◽  
Tim Schrabback ◽  
Thomas H. Reiprich ◽  
Lorenzo Lovisari ◽  
Steven W. Allen ◽  
...  
Keyword(s):  
Temperature Profile ◽  
Gravitational Lensing ◽  
Mass Fraction ◽  
High Redshift ◽  
Galaxy Cluster ◽  
Cooling Time ◽  
Weak Lensing ◽  
Imaging Data ◽  
Weak Gravitational Lensing ◽  
X Ray

Context. Observations of relaxed, massive, and distant clusters can provide important tests of standard cosmological models, for example by using the gas mass fraction. To perform this test, the dynamical state of the cluster and its gas properties have to be investigated. X-ray analyses provide one of the best opportunities to access this information and to determine important properties such as temperature profiles, gas mass, and the total X-ray hydrostatic mass. For the last of these, weak gravitational lensing analyses are complementary independent probes that are essential in order to test whether X-ray masses could be biased. Aims. We study the very luminous, high redshift (z = 0.902) galaxy cluster Cl J120958.9+495352 using XMM-Newton data. We measure global cluster properties and study the temperature profile and the cooling time to investigate the dynamical status with respect to the presence of a cool core. We use Hubble Space Telescope (HST) weak lensing data to estimate its total mass and determine the gas mass fraction. Methods. We perform a spectral analysis using an XMM-Newton observation of 15 ks cleaned exposure time. As the treatment of the background is crucial, we use two different approaches to account for the background emission to verify our results. We account for point spread function effects and deproject our results to estimate the gas mass fraction of the cluster. We measure weak lensing galaxy shapes from mosaic HST imaging and select background galaxies photometrically in combination with imaging data from the William Herschel Telescope. Results. The X-ray luminosity of Cl J120958.9+495352 in the 0.1–2.4 keV band estimated from our XMM-Newton data is LX = (13.4−1.0+1.2) × 1044 erg/s and thus it is one of the most X-ray luminous clusters known at similarly high redshift. We find clear indications for the presence of a cool core from the temperature profile and the central cooling time, which is very rare at such high redshifts. Based on the weak lensing analysis, we estimate a cluster mass of M500 / 1014 M⊙ = 4.4−2.0+2.2(star.) ± 0.6(sys.) and a gas mass fraction of fgas,2500 = 0.11−0.03+0.06 in good agreement with previous findings for high redshift and local clusters.

scholarly journals Mass Bias of Weak-lensing Shear-selected Galaxy Cluster Samples

2020 ◽  
Vol 891 (2) ◽  
pp. 139 ◽  
Author(s):  
Kai-Feng Chen ◽  
Masamune Oguri ◽  
Yen-Ting Lin ◽  
Satoshi Miyazaki
Keyword(s):  
Galaxy Cluster ◽  
Weak Lensing ◽  
Mass Bias

scholarly journals Deprojection of Galaxy Cluster X‐Ray, Sunyaev‐Zeldovich Temperature Decrement, and Weak‐Lensing Mass Maps

2001 ◽  
Vol 561 (2) ◽  
pp. 600-620 ◽  
Author(s):  
S. Zaroubi ◽  
G. Squires ◽  
G. de Gasperis ◽  
A. E. Evrard ◽  
Y. Hoffman ◽  
...  
Keyword(s):  
Galaxy Cluster ◽  
Weak Lensing ◽  
X Ray

scholarly journals The Double Galaxy Cluster A2465. III. X-Ray and Weak-lensing Observations

2017 ◽  
Vol 844 (1) ◽  
pp. 67 ◽  
Author(s):  
Gary A. Wegner ◽  
Keiichi Umetsu ◽  
Sandor M. Molnar ◽  
Mario Nonino ◽  
Elinor Medezinski ◽  
...  
Keyword(s):  
Galaxy Cluster ◽  
Weak Lensing ◽  
X Ray ◽  
Double Galaxy

scholarly journals Dark Energy Surveyed Year 1 results: calibration of cluster mis-centring in the redMaPPer catalogues

2019 ◽  
Vol 487 (2) ◽  
pp. 2578-2593 ◽  
Author(s):  
Y Zhang ◽  
T Jeltema ◽  
D L Hollowood ◽  
S Everett ◽  
E Rozo ◽  
...  
Keyword(s):  
Dark Energy ◽  
Gamma Distribution ◽  
Galaxy Cluster ◽  
Weak Lensing ◽  
Descriptive Model ◽  
X Ray ◽  
Projected Distance

Abstract The centre determination of a galaxy cluster from an optical cluster finding algorithm can be offset from theoretical prescriptions or N-body definitions of its host halo centre. These offsets impact the recovered cluster statistics, affecting both richness measurements and the weak lensing shear profile around the clusters. This paper models the centring performance of the redMaPPer cluster finding algorithm using archival X-ray observations of redMaPPer-selected clusters. Assuming the X-ray emission peaks as the fiducial halo centres, and through analysing their offsets to the redMaPPer centres, we find that ${\sim } 75\pm 8 {{\ \rm per\ cent}}$ of the redMaPPer clusters are well centred and the mis-centred offset follows a Gamma distribution in normalized, projected distance. These mis-centring offsets cause a systematic underestimation of cluster richness relative to the well-centred clusters, for which we propose a descriptive model. Our results enable the DES Y1 cluster cosmology analysis by characterizing the necessary corrections to both the weak lensing and richness abundance functions of the DES Y1 redMaPPer cluster catalogue.

scholarly journals Comparing different mass estimators for a large subsample of the Planck-ESZ clusters

2020 ◽  
Vol 644 ◽  
pp. A78
Author(s):  
L. Lovisari ◽  
S. Ettori ◽  
M. Sereno ◽  
G. Schellenberger ◽  
W. R. Forman ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Small Sample ◽  
Weak Lensing ◽  
Mass Measurements ◽  
X Ray ◽  
Mass Bias ◽  
Significant Difference ◽  
The Mean ◽  
Cluster Abundance

Context. Total mass is arguably the most fundamental property for cosmological studies with galaxy clusters. The individual cluster masses can be obtained with different methods, each with its own biases and limitations. Systematic differences in mass measurements can strongly impact the determination of the hydrostatic bias and of the mass-observable relations, key requirements of many cluster abundance studies. Aims. We investigate the present differences in the mass estimates obtained through independent X-ray, weak-lensing, and dynamical studies using a large subsample of the Planck-ESZ clusters. We also discuss the implications for mass bias analyses. Methods. After assessing the systematic differences in the X-ray-derived masses reported by distinct groups, we examine the mass estimates obtained with independent methods and quantify the differences as the mean ratio 1-b = MHE/MWL, dyn, where HE refers to hydrostatic masses obtained from X-ray observations, WL refers to the results of weak-lensing measurements, and dyn refers to the mass estimates either from velocity dispersion or from the caustic technique. So defined, the 1-b parameter includes all possible astrophysical, observational, and methodological biases in one single value. Results. Recent X-ray masses reported by independent groups show average differences smaller than ∼10%, posing a strong limit on the systematics that can be ascribed to the differences in the X-ray analysis when studying the hydrostatic bias. The mean ratio between our X-ray masses and the weak-lensing masses in the LC2-single catalog is 1-b = 0.74 ± 0.06, which corresponds to a mass bias of 26 ± 6%, a value insufficient to reconcile the Planck cluster abundance and cosmic microwave background results. However, the mean mass ratios inferred from the WL masses of different projects vary by a large amount, with APEX-SZ showing a bias consistent with zero (1-b = 1.02 ± 0.12), LoCuSS and CCCP/MENeaCS showing a significant difference (1-b = 0.76 ± 0.09 and 1-b = 0.77 ± 0.10, respectively), and WtG pointing to the largest deviation (1-b = 0.61 ± 0.12), which would substantially reduce the tension between the Planck results. Because of small differences between our M − YX relation and the one used by the Planck collaboration, our X-ray masses are on average 7% lower (4% at the same physical radius) than the Planck masses and can further reduce the required bias. At odds with the WL results, the dynamical mass measurements show better agreement with the X-ray hydrostatic masses, although there are significant differences when relaxed or disturbed clusters are used. However, the comparison is currently limited by the small sample sizes. Conclisions. The systematic differences between total masses obtained with recent independent X-ray analyses are smaller than those found in previous studies. This shifts the focus to WL and dynamical studies for a better convergence of the level of mass bias. However, the ratios obtained using different mass estimators suggest that there are still systematics that are not accounted for in all the techniques used to recover cluster masses. This prevents the determination of firm constraints on the level of hydrostatic mass bias in galaxy clusters.

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