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Related papers: Constraints on Cluster Properties Using X-ray and …

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We study constrained clustering, where constraints guide the clustering process. In existing works, two categories of constraints have been widely explored, namely pairwise and cardinality constraints. Pairwise constraints enforce the…

Machine Learning · Computer Science 2023-01-30 Adel Bibi , Ali Alqahtani , Bernard Ghanem

Galaxy clustering and galaxy-galaxy lensing probe the connection between galaxies and their dark matter haloes in complementary ways. On one hand, the halo occupation statistics inferred from the observed clustering properties of galaxies…

Astrophysics · Physics 2009-11-19 Marcello Cacciato , Frank C. van den Bosch , Surhud More , Ran Li , H. J. Mo , Xiaohu Yang

The abundance of rich clusters is a strong constraint on the mass power spectrum. The current constraint can be expressed in the form $\sigma_8 \Omega_m^{\gamma} = 0.5 \pm 0.1$ where $\sigma_8$ is the $rms$ mass fluctuation on 8 $h^{-1}$…

Astrophysics · Physics 2009-09-15 Limin Wang , Paul J. Steinhardt

We forecast constraints on the amplitude of matter clustering sigma_8(z) achievable with the combination of cluster weak lensing and number counts, in current and next-generation weak lensing surveys. We advocate an approach, analogous to…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-29 Hao-Yi Wu , David H. Weinberg , Andrés N. Salcedo , Benjamin D. Wibking

The problem of clustering noisy and incompletely observed high-dimensional data points into a union of low-dimensional subspaces and a set of outliers is considered. The number of subspaces, their dimensions, and their orientations are…

Machine Learning · Statistics 2015-08-24 Reinhard Heckel , Helmut Bölcskei

We investigate how galaxies in VIPERS (the VIMOS Public Extragalactic Redshift Survey) inhabit the cosmological density field by examining the correlations across the observable parameter space of galaxy properties and clustering strength.…

Context: We present the first Cosmological Parameter inferences from eROSITA X-ray observations of galaxy clusters using a Machine Learning algorithm. Methods: We train a Random Forest using mock catalogs of clusters from Magneticum…

The upcoming XMM Large Scale Structure Survey (XMM-LSS) will ultimately provide a unique mapping of the distribution of X-ray sources in a contiguous 64 sq. deg. region. In particular, it will provide the 3-dimensional location of about 900…

Astrophysics · Physics 2009-11-07 Alexandre Refregier , Ivan Valtchanov , Marguerite Pierre

Clustering large, mixed data is a central problem in data mining. Many approaches adopt the idea of k-means, and hence are sensitive to initialisation, detect only spherical clusters, and require a priori the unknown number of clusters. We…

Machine Learning · Statistics 2020-11-13 Joshua Tobin , Mimi Zhang

Quality assessments of models in unsupervised learning and clustering verification in particular have been a long-standing problem in the machine learning research. The lack of robust and universally applicable cluster validity scores often…

Machine Learning · Statistics 2018-03-30 Luzie Helfmann , Johannes von Lindheim , Mattes Mollenhauer , Ralf Banisch

We show that the abundance and redshift distribution ($dN/dz$) of galaxy clusters in future high--yield cluster surveys, combined with the spatial power spectrum ($P_c(k)$) of the same clusters, can place significant constraints on the…

Astrophysics · Physics 2008-11-26 Sheng Wang , Justin Khoury , Zoltan Haiman , Morgan May

We present forecasts for constraints on deviations from Gaussian distribution of primordial density perturbations from future X-ray surveys of galaxy clusters. Our analysis is based on computing the Fisher-Matrix for number counts and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 B. Sartoris , S. Borgani , C. Fedeli , S. Matarrese , L. Moscardini , P. Rosati , J. Weller

We put constraints on the main cosmological parameters of different spatially flat cosmological models by combining the recent clustering results of XMM-Newton soft (0.5-2 keV) X-ray sources, which have a redshift distribution with median…

Astrophysics · Physics 2009-11-10 Spyros Basilakos , Manolis Plionis

Clusters of galaxies are used in a variety of ways to do cosmology. Some of them are presented here. Their X-ray emitting gas allows us to determine the baryon fraction, dark matter distribution and the matter density $\Omega_{m}$ of the…

Astrophysics · Physics 2007-05-23 Africa Castillo-Morales , Sabine Schindler

We present constraints on cosmic structure growth from the analysis of galaxy clustering and galaxy-galaxy lensing with galaxies from the Dark Energy Spectroscopic Instrument (DESI) Data Release 1. We analyze four samples drawn from the…

The statistical properties of galaxy clusters can only be used for cosmological purposes if observational effects related to cluster detection are accurately characterized. These effects include the selection function associated to cluster…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-18 Michel Aguena , Marcos Lima

We derive cosmological constraints on the matter density, \om, and the amplitude of fluctuations, \sig, using $\mathtt{GalWCat19}$, a catalog of 1800 galaxy clusters we identified in the Sloan Digital Sky Survey-DR13 spectroscopic data set…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-07 Mohamed H. Abdullah , Anatoly Klypin , Gillian Wilson

XMM and Chandra opened a new area for the study of clusters of galaxies. Not only for cluster physics but also, for the detection of faint and distant clusters that were inaccessible with previous missions. This article presents 66…

The knowledge of the redshift of multiple images in cluster-lenses allows to determine precisely the total projected mass within the Einstein radius. The observation of various multiple images in a same cluster is opening new possibilities…

Astrophysics · Physics 2007-05-23 G. Golse , J. -P. Kneib , G. Soucail

In the framework of the hierarchical model the intra-cluster medium properties of galaxy clusters are tightly linked to structure formation, which makes X-ray surveys well suited for cosmological studies. To constrain cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-07 Florian Käfer , Alexis Finoguenov , Dominique Eckert , Jeremy S. Sanders , Thomas H. Reiprich , Kirpal Nandra