English
Related papers

Related papers: Galaxy cluster characterization with machine learn…

200 papers

Accurate measurements of the mass distribution in galaxy and cluster halos are essential to test the cold dark matter (CDM) paradigm. The cosmological model predicts a universal shape for the density profile in all halos, independent of…

Astrophysics · Physics 2009-09-29 L. M. Voigt , A. C. Fabian

Our current knowledge of the thermodynamic properties of galaxy clusters comes primarily from detailed studies of clusters selected by their minority components: hot baryons. Most of these studies select the clusters using the component…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-15 S. Andreon , M. Radovich , A. Moretti , F. -X. Desert , T. Hamana , M. Pizzardo , C. Romero , H. Roussel , G. Trinchieri

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

The density profile of a cool core of intracluster gas is investigated for a cluster of galaxies that is initially in the virial equilibrium state, and then undergoes radiative cooling. The initial gas profile is derived under the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Naomi Ota , Kiyokazu Onzuka , Kuniaki Masai

We train three convolutional neural networks (CNNs) to classify galaxies with Galaxy Zoo 2 dataset and extract the activations from the last fully connected layer or the last average pooling layer of CNNs to study the high-dimensional…

Astrophysics of Galaxies · Physics 2018-07-17 Jia-Ming Dai , Jizhou Tong

We present the analysis of a local (z = 0.04 - 0.2) sample of 31 galaxy clusters with the aim of measuring the density of the X-ray emitting gas in cluster outskirts. We compare our results with numerical simulations to set constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-08 D. Eckert , F. Vazza , S. Ettori , S. Molendi , D. Nagai , E. T. Lau , M. Roncarelli , M. Rossetti , S. L. Snowden , F. Gastaldello

We present a simple model to describe the dark matter density, the gas density, and the gas temperature profiles of galaxy clusters. Analytical expressions for these quantities are given in terms of only five free parameters with a clear…

Astrophysics · Physics 2009-11-13 Y. Ascasibar , J. M. Diego

We report the results of a study which assembles deep observations with the ACIS-I instrument on the Chandra Observatory to study the evolution in the core properties of a sample of galaxy groups and clusters out to redshifts $z\approx…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Aurelia Pascut , Trevor J. Ponman

The X-ray properties of a relaxed cluster of galaxies are determined primarily by its gravitational potential well and the entropy distribution of its intracluster gas. That entropy distribution reflects both the accretion history of the…

Astrophysics · Physics 2009-11-13 Megan Donahue , Donald J. Horner , Kenneth W. Cavagnolo , G. Mark Voit

(Abridged) This is the second in a series of papers in which we derive simultaneous constraints on cosmology and X-ray scaling relations using observations of massive, X-ray flux-selected galaxy clusters. The data set consists of 238…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Adam Mantz , Steven W. Allen , Harald Ebeling , David Rapetti , Alex Drlica-Wagner

The X-ray morphologies of clusters of galaxies display significant variations, reflecting their dynamical histories and the nonlinear dependence of X-ray emissivity on the density of the intracluster gas. Qualitative and quantitative…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-02 Maya Benyas , Jordan Pfeifer , Adam B. Mantz , Steven W. Allen , Elise Darragh-Ford

Morphology is often used to infer the state of relaxation of galaxy clusters. The regularity, symmetry, and degree to which a cluster is centrally concentrated inform quantitative measures of cluster morphology. The Cluster Lensing and…

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

To better constrain models of cool core galaxy cluster formation, we have used X-ray observations taken from the Chandra and ROSAT archives to examine the properties of cool core and non-cool core clusters, especially beyond the cluster…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-15 Jason W. Henning , Brennan Gantner , Jack O. Burns , Eric J. Hallman

The reconstruction of galaxy cluster's gas density profiles is usually performed by assuming spherical symmetry and averaging the observed X-ray emission in circular annuli. In the case of a very inhomogeneous and asymmetric gas…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 D. Eckert , M. Roncarelli , S. Ettori , S. Molendi , F. Vazza , F. Gastaldello , M. Rossetti

Knowledge of the structure of galaxy clusters is essential for an understanding of large scale structure in the universe, and may provide important clues to the nature of dark matter. Moreover, the shape of the dark matter distribution in…

Astrophysics · Physics 2009-11-07 J. S. Arabadjis , M. W. Bautz , G. Arabadjis

Nowadays, Machine Learning techniques offer fast and efficient solutions for classification problems that would require intensive computational resources via traditional methods. We examine the use of a supervised Random Forest to classify…

Astrophysics of Galaxies · Physics 2022-06-22 I. Marini , S. Borgani , A. Saro , G. Murante , G. L. Granato , C. Ragone-Figueroa , G. Taffoni

We investigate the detection of Cool Cores (CCs) in the distant galaxy cluster population, with the purpose of measuring the CC fraction out to redshift 0.7 < z < 1.4. Using a sample of nearby clusters spanning a wide range of morphologies,…

We present results obtained from a set of cosmological hydrodynamic simulations of galaxy clusters, aimed at comparing predictions with observational data on the diversity between cool-core (CC) and non-cool-core (NCC) clusters. Our…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-04 E. Rasia , S. Borgani , G. Murante , S. Planelles , A. M. Beck , V. Biffi , C. Ragone-Figueroa , G. L. Granato , L. K. Steinborn , K. Dolag

There are well-observed differences between cool-core (CC) and non-cool-core (NCC) clusters, but the origin of this distinction is still largely unknown. Competing theories can be divided into internal (inside-out), in which internal…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-20 Elinor Medezinski , Nicholas Battaglia , Jean Coupon , Renyue Cen , Massimo Gaspari , Michael A. Strauss , David N. Spergel