Cosmic variance of the galaxy cluster weak lensing signal

ABSTRACT We present a detailed study of the shapes and alignments of different galaxy cluster components using hydrodynamical simulations. We compute shape parameters from the dark matter (DM) distribution, the galaxy members and the intracluster light (ICL). We assess how well the DM cluster shape can be constrained by means of the identified galaxy member positions and the ICL. Further, we address the dilution factor introduced when estimating the cluster elongation using weak-lensing stacking techniques, which arises due to the misalignment between the total surface mass distribution and the distribution of luminous tracers. The dilution is computed considering the alignment between the DM and the brightest cluster galaxy, the galaxy members and the ICL. Our study shows that distributions of galaxy members and ICL are less spherical than the DM component, although both are well aligned with the semimajor axis of the latter. We find that the distribution of galaxy members hosted in more concentrated subhaloes is more elongated than the distribution of the DM. Moreover, these galaxies are better aligned with the DM component compared to the distribution of galaxies hosted in less concentrated subhaloes. We conclude that the positions of galaxy members can be used as suitable tracers to estimate the cluster surface density orientation, even when a low number of members is considered. Our results provide useful information for interpreting the constraints on the shapes of galaxy clusters in observational studies.

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Weak lensing mass reconstruction of the galaxy cluster Abell 209

Astronomy and Astrophysics ◽

10.1051/0004-6361:20066994 ◽

2007 ◽

Vol 467 (2) ◽

pp. 427-436 ◽

Cited By ~ 17

Author(s):

S. Paulin-Henriksson ◽

V. Antonuccio-Delogu ◽

C. P. Haines ◽

M. Radovich ◽

A. Mercurio ◽

...

Keyword(s):

Galaxy Cluster ◽

Weak Lensing ◽

The Galaxy ◽

Mass Reconstruction

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Hubble Space TelescopeACS Weak‐Lensing Analysis of the Galaxy Cluster RDCS 1252.9−2927 atz= 1.24

The Astrophysical Journal ◽

10.1086/428427 ◽

2005 ◽

Vol 623 (1) ◽

pp. 42-56 ◽

Cited By ~ 33

Author(s):

M. Lombardi ◽

P. Rosati ◽

J. P. Blakeslee ◽

S. Ettori ◽

R. Demarco ◽

...

Keyword(s):

Galaxy Cluster ◽

Weak Lensing ◽

The Galaxy

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PROBING THE CLUSTER MASS DISTRIBUTION USING SUBARU WEAK LENSING DATA

Modern Physics Letters A ◽

10.1142/s0217732307025340 ◽

2007 ◽

Vol 22 (25n28) ◽

pp. 2099-2106 ◽

Cited By ~ 13

Author(s):

KEIICHI UMETSU ◽

MASAHIRO TAKADA ◽

TOM BROADHURST

Keyword(s):

Mass Distribution ◽

Galaxy Cluster ◽

Entropy Method ◽

Weak Lensing ◽

Wide Field ◽

Imaging Data ◽

The Galaxy ◽

Dimensional Reconstruction ◽

Mass Profile ◽

Good Agreement

We present results from a weak lensing analysis of the galaxy cluster A1689 (z = 0.183) based on deep wide-field imaging data taken with Suprime-Cam on Subaru telescope. A maximum entropy method has been used to reconstruct directly the projected mass distribution of A1689 from combined lensing distortion and magnification measurements of red background galaxies. The resulting mass distribution is clearly concentrated around the cD galaxy, and mass and light in the cluster are similarly distributed in terms of shape and orientation. The azimuthally-averaged mass profile from the two-dimensional reconstruction is in good agreement with the earlier results from the Subaru one-dimensional analysis of the weak lensing data, supporting the assumption of quasi-circular symmetry in the projected mass distribution of the cluster.

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Probing Saraswati’s heart: evaluating the dynamical state of the massive galaxy cluster A2631 through a comprehensive weak-lensing and dynamical analysis

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3575 ◽

2020 ◽

Vol 501 (1) ◽

pp. 756-768

Author(s):

R Monteiro-Oliveira ◽

A C Soja ◽

A L B Ribeiro ◽

J Bagchi ◽

S Sankhyayan ◽

...

Keyword(s):

Galaxy Cluster ◽

Dynamical Analysis ◽

Weak Lensing ◽

Data Sets ◽

Dynamical State ◽

Massive Structure ◽

The Galaxy ◽

Dynamics Of Galaxies ◽

Massive Galaxy

ABSTRACT In this work, we investigate the dynamical state of the galaxy cluster Abell 2631, a massive structure located at the core of the Saraswati supercluster. To do this, we first solve a tension found in the literature regarding the weak-lensing mass determination of the cluster. We do this through a comprehensive weak-lensing analysis, exploring the power of the combination of shear and magnification data sets. We find $M_{200}^{\rm wl} = 8.7_{-2.9}^{+2.5} \times 10^{14}$ M⊙. We also determined the mass based on the dynamics of spectroscopic members, corresponding to $M_{200}^{\rm dy} = 12.2\pm 3.0 \times 10^{14}$ M⊙, consistent within a 68 per cent CL with the weak-lensing estimate. The scenarios provided by the mass distribution and dynamics of galaxies are reconciled with those provided by X-ray observations in a scenario where A2631 is observed at a late stage of merging.

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

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320003105 ◽

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.

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Reconciling galaxy cluster shapes, measured by theorists versus observers

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3193 ◽

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.

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DeepChandraobservation of the galaxy cluster WARPJ1415.1+3612 atz=1

Astronomy and Astrophysics ◽

10.1051/0004-6361/201118162 ◽

2012 ◽

Vol 539 ◽

pp. A105 ◽

Cited By ~ 20

Author(s):

J. S. Santos ◽

P. Tozzi ◽

P. Rosati ◽

M. Nonino ◽

G. Giovannini

Keyword(s):

Galaxy Cluster ◽

The Galaxy

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

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stw3322 ◽

2016 ◽

Vol 466 (3) ◽

pp. 3663-3673 ◽

Cited By ~ 12

Author(s):

Melanie Simet ◽

Nicholas Battaglia ◽

Rachel Mandelbaum ◽

Uroš Seljak

Keyword(s):

Galaxy Cluster ◽

Weak Lensing ◽

X Ray ◽

Mass Bias

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

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731222 ◽

2018 ◽

Vol 611 ◽

pp. A50 ◽

Cited By ~ 5

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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