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Related papers: Weighing Galaxy Clusters with Gas. I. On the Metho…

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We present a modelization of the non-thermal pressure, $P_{NT}$, and we apply it to the X-ray (and Sunayev-Zel'dovich) derived radial profiles of the X-COP galaxy clusters. We relate the amount of non-thermal pressure support to the…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-29 S. Ettori , D. Eckert

Clusters of galaxies are the largest gravitationally bound systems and therefore provide an important way of studying the formation and evolution of the large scale structure of the Universe. Cluster evolution can be inferred from…

Gravitational hydrodynamics acknowledges that hydrodynamics is essentially nonlinear and viscous. In the plasma, at $z=5100$, the viscous length enters the horizon and causes fragmentation into plasma clumps surrounded by voids. The latter…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-03 Theo M. Nieuwenhuizen , Carl H. Gibson , Rudolph E. Schild

Velocity dispersions have been employed as a method to measure masses of clusters. To complement this conventional method, we explore the possibility of constraining cluster masses from the stacked phase space distribution of galaxies at…

Astrophysics of Galaxies · Physics 2019-09-04 Akinari Hamabata , Masamune Oguri , Takahiro Nishimichi

If a galaxy cluster is effectively in dynamical equilibrium then all galaxy populations within the cluster must have distributions in velocity and position that individually reflect the same underlying mass distribution, although the…

Astrophysics · Physics 2016-08-30 Carlberg , Yee , Ellingson , Morris , Abraham , Gravel , Pritchet , Smecker-Hane , Hartwick , Hesser , Hutchings , Oke

The study of galaxy cluster outskirts has emerged as one of the new frontiers in extragalactic astrophysics and cosmology with the advent of new observations in X-ray and microwave. However, the thermodynamic properties and chemical…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-24 Camille Avestruz , Erwin T. Lau , Daisuke Nagai , Alexey Vikhlinin

We present a simultaneous analysis of galaxy cluster scaling relations between weak-lensing mass and multiple cluster observables, across a wide range of wavelengths, that probe both gas and stellar content. Our new hierarchical Bayesian…

It is now possible for hydrodynamical simulations to reproduce a representative galaxy population. Accordingly, it is timely to assess critically some of the assumptions of traditional semi-analytic galaxy formation models. We use the Eagle…

Machine learning (ML) techniques, in particular supervised regression algorithms, are a promising new way to use multiple observables to predict a cluster's mass or other key features. To investigate this approach we use the \textsc{MACSIS}…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-16 Thomas J. Armitage , Scott T. Kay , David J. Barnes

Galaxy and galaxy clusters exhibit tight robust physical scaling relations between baryons and system dynamics. One such phenomenon is mass discrepancy with two leading solution spaces occupied by LCDM and MOND. Here, we propose an…

Astrophysics of Galaxies · Physics 2023-07-11 Jeffrey M. La Fortune

Galaxy clusters can be used as powerful cosmological probes, provided one can obtain accurate mass estimates, which requires a precise knowledge of the underlying astrophysics of galaxy clusters. For these purposes, spatially resolved…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-12 R. Wicker , M. De Petris , A. Ferragamo , I. Bartalucci , G. Yepes , E. Rasia , R. Adam , W. Cui , F. Mayet , L. Perotto , M. Muñoz-Echeverría

The time evolution of initially balanced, rapidly rotating models for an isolated disk of highly flattened galaxies of stars is calculated. The method of direct integration of the Newtonian equations of motion of stars over a time span of…

Astrophysics · Physics 2007-05-23 Evgeny Griv , Michael Gedalin , Edward Liverts , David Eichler , Yehoshua Kimhi , Chi Yuan

We propose a new cosmological test of gravity, by using the observed mass fraction of X-ray emitting gas in massive galaxy clusters. The cluster gas fraction, believed to be a fair sample of the average baryon fraction in the Universe, is a…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-23 Baojiu Li , Jian-hua He , Liang Gao

Measurements of the galaxy density and weak-lensing profiles of galaxy clusters typically rely on an assumed cluster center, which is taken to be the brightest cluster galaxy or other proxies for the true halo center. Departure of the…

Instrumentation and Methods for Astrophysics · Physics 2024-08-21 Matthew Currie , Kyle Miller , Tae-Hyeon Shin , Eric Baxter , Bhuvnesh Jain

The mass measurement of galaxy clusters is an important tool for the determination of cosmological parameters describing the matter and energy content of the Universe. However, the standard methods rely on various assumptions about the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Martina Falco , Steen H. Hansen , Radoslaw Wojtak , Thejs Brinckmann , Mikkel Lindholmer , Stefania Pandolfi

One of the main limitations in precision cluster cosmology arises from systematic errors and uncertainties in estimating cluster masses. Using the Mock-X pipeline, we produce synthetic X-ray images and derive cluster and galaxy group X-ray…

A kinetic and hydrodynamic descriptions are developed in order to analyze the instabilities of a granular gas in the presence of a gravitational field. In the kinetic description the Boltzmann equation is coupled with the Poisson equation,…

Statistical Mechanics · Physics 2019-11-26 Gilberto Medeiros Kremer

We investigate the impact of chameleon-type f(R) gravity models on the properties of galaxy clusters and groups. Our f(R) simulations follow for the first time also the hydrodynamics of the intracluster and intragroup medium. This allows us…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Christian Arnold , Ewald Puchwein , Volker Springel

We study the projection effects on various observables of clusters of galaxies at redshift near zero, including cluster richness, velocity dispersion, X-ray luminosity, three total mass estimates (velocity-based, temperature-based and…

Astrophysics · Physics 2009-10-28 Renyue Cen

We quantify departures from hydrodynamical and centrifugal equilibrium in the gas discs of low-mass ($10^{10.75}<M_\mathrm{200c}/\mathrm{M}_\odot<10^{11}$) galaxies from the COLIBRE cosmological hydrodynamical simulations. We evaluate the…