Clusters of Galaxies: Beyond the Thermal View

Clusters of Galaxies: Beyond the Thermal View PDF Author: Jelle Kaastra
Publisher: Springer Science & Business Media
ISBN: 0387788751
Category : Science
Languages : en
Pages : 418

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Book Description
The existence of soft excess emission originating from clusters of galaxies, de ned as em- sion detected below 1 keV in excess over the usual thermal emission from hot intracluster gas (hereafter the ICM) has been claimed since 1996. Soft excesses are particularly - portant to detect because they may (at least partly) be due to thermal emission from the Warm-Hot Intergalactic Medium, where as much as half of the baryons of the Universe could be. They are therefore of fundamental cosmological importance. Soft excess emission has been observed (and has also given rise to controversy) in a number of clusters, mainly raising the following questions: (1) Do clusters really show a soft excess? (2) If so, from what spatial region(s) of the cluster does the soft excess or- inate? (3) Is this excess emission thermal, originating from warm-hot intergalactic gas (at 6 temperatures of?10 K), or non-thermal, in which case several emission mechanisms have been proposed. Interestingly, some of the non-thermal mechanisms suggested to account for soft excess emission can also explain the hard X-ray emission detected in some clusters, for example by RXTE and BeppoSAX (also see Petrosian et al. 2008—Chap. 10, this issue; Rephaeli et al. 2008—Chap. 5, this issue).

Clusters of Galaxies: Beyond the Thermal View

Clusters of Galaxies: Beyond the Thermal View PDF Author: Jelle Kaastra
Publisher: Springer Science & Business Media
ISBN: 0387788751
Category : Science
Languages : en
Pages : 418

Get Book

Book Description
The existence of soft excess emission originating from clusters of galaxies, de ned as em- sion detected below 1 keV in excess over the usual thermal emission from hot intracluster gas (hereafter the ICM) has been claimed since 1996. Soft excesses are particularly - portant to detect because they may (at least partly) be due to thermal emission from the Warm-Hot Intergalactic Medium, where as much as half of the baryons of the Universe could be. They are therefore of fundamental cosmological importance. Soft excess emission has been observed (and has also given rise to controversy) in a number of clusters, mainly raising the following questions: (1) Do clusters really show a soft excess? (2) If so, from what spatial region(s) of the cluster does the soft excess or- inate? (3) Is this excess emission thermal, originating from warm-hot intergalactic gas (at 6 temperatures of?10 K), or non-thermal, in which case several emission mechanisms have been proposed. Interestingly, some of the non-thermal mechanisms suggested to account for soft excess emission can also explain the hard X-ray emission detected in some clusters, for example by RXTE and BeppoSAX (also see Petrosian et al. 2008—Chap. 10, this issue; Rephaeli et al. 2008—Chap. 5, this issue).

Clusters of Galaxies

Clusters of Galaxies PDF Author:
Publisher:
ISBN: 9780387788739
Category :
Languages : en
Pages : 418

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Book Description


Clusters of Galaxies: Beyond the Thermal View

Clusters of Galaxies: Beyond the Thermal View PDF Author: Jelle Kaastra
Publisher: Springer
ISBN: 9780387523378
Category : Science
Languages : en
Pages : 0

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Book Description
The existence of soft excess emission originating from clusters of galaxies, de ned as em- sion detected below 1 keV in excess over the usual thermal emission from hot intracluster gas (hereafter the ICM) has been claimed since 1996. Soft excesses are particularly - portant to detect because they may (at least partly) be due to thermal emission from the Warm-Hot Intergalactic Medium, where as much as half of the baryons of the Universe could be. They are therefore of fundamental cosmological importance. Soft excess emission has been observed (and has also given rise to controversy) in a number of clusters, mainly raising the following questions: (1) Do clusters really show a soft excess? (2) If so, from what spatial region(s) of the cluster does the soft excess or- inate? (3) Is this excess emission thermal, originating from warm-hot intergalactic gas (at 6 temperatures of?10 K), or non-thermal, in which case several emission mechanisms have been proposed. Interestingly, some of the non-thermal mechanisms suggested to account for soft excess emission can also explain the hard X-ray emission detected in some clusters, for example by RXTE and BeppoSAX (also see Petrosian et al. 2008—Chap. 10, this issue; Rephaeli et al. 2008—Chap. 5, this issue).

Clusters of Galaxies: Physics and Cosmology

Clusters of Galaxies: Physics and Cosmology PDF Author: Andrei M. Bykov
Publisher: Springer
ISBN: 9789402417364
Category : Science
Languages : en
Pages : 535

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Book Description
Clusters of galaxies are large assemblies of galaxies, hot gas and dark matter bound together by gravity. Galaxy clusters are now one of the most important cosmological probes to test the standard cosmological models. Constraints on the Dark Energy equation of state from the cluster number density measurements, deviations from the Gaussian perturbation models, the Sunyaev-Zeldovich effect as well as the dark matter proles are among the issues to be studied with clusters. The baryonic composition of clusters is dominated by hot gas that is in quasi-hydrostatic equilibrium within the dark matter-dominated gravitational potential well of the cluster. The hot gas is visible through spatially extended thermal X-ray emission, and it has been studied extensively both for assessing its physical properties and as a tracer of the large-scale structure of the Universe. Magnetic fields as well as a number of non-thermal plasma processes play a role in clusters of galaxies as we observe from radioastronomical observations. The goal of this volume is to review these processes and to investigate how they are interlinked. Overall, these papers provide a timely and comprehensive review of the multi-wavelength observations and theoretical understanding of clusters of galaxies in the cosmological context. Thus, the volume will be particularly useful to postgraduate students and researchers active in various areas of astrophysics and space science. Originally published in Space Science Reviews in the Topical Collection "Clusters of Galaxies: Physics and Cosmology"

Clusters and Superclusters of Galaxies

Clusters and Superclusters of Galaxies PDF Author: A.C. Fabian
Publisher: Springer Science & Business Media
ISBN: 9401124825
Category : Science
Languages : en
Pages : 373

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Book Description
Clusters and superclusters of galaxies are the largest objects in the Universe. They have been the subject of intense observational studies at a variety of wavelengths, from radio to X-ray which has provoked much theoretical debate and advanced our understanding of the recent evolution of the large-scale structure of the Universe. The current status of the subject is reviewed in this volume by active researchers who lectured at a NATO Advanced Study Institute held in Cambridge, England in July 1991. Much of the material is presented in a pedagogical manner and will appeal to scientists, astronomers and graduate students interested in extragalactic astronomy.

Solar, Stellar and Galactic Connections between Particle Physics and Astrophysics

Solar, Stellar and Galactic Connections between Particle Physics and Astrophysics PDF Author: Alberto Carramiñana
Publisher: Springer Science & Business Media
ISBN: 1402055757
Category : Science
Languages : en
Pages : 306

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Book Description
This book collects extended and specialized reviews on topics linking astrophysics and particle physics at a level between a graduate student and a young researcher. The book also includes three reviews on observational techniques used in forefront astrophysics and short articles on research performed in Latin America. The reviews, updated and written by specialized researchers, describe the state of the art in the related research topics.

A Pan-Chromatic View of Clusters of Galaxies and the Large-Scale Structure

A Pan-Chromatic View of Clusters of Galaxies and the Large-Scale Structure PDF Author: Manolis Plionis
Publisher: Springer Science & Business Media
ISBN: 1402069405
Category : Science
Languages : en
Pages : 476

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Book Description
The reviews presented in this volume cover a huge range of cluster of galaxies topics. Readers will find the book essential reading on subjects such as the physics of the ICM gas, the internal cluster dynamics, and the detection of clusters using different observational techniques. The expert chapter authors also cover the huge advances being made in analytical or numerical modeling of clusters, weak and strong lensing effects, and the large scale structure as traced by clusters.

Merging Processes in Galaxy Clusters

Merging Processes in Galaxy Clusters PDF Author: L. Feretti
Publisher: Springer Science & Business Media
ISBN: 0306480964
Category : Science
Languages : en
Pages : 320

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Book Description
Mergers are the mechanisms by which galaxy clusters are assembled through the hierarchical growth of smaller clusters and groups. Major cluster mergers are the most energetic events in the Universe since the Big Bang. Many of the observed properties of clusters depend on the physics of the merging process. These include substructure, shock, intra cluster plasma temperature and entropy structure, mixing of heavy elements within the intra cluster medium, acceleration of high-energy particles, formation of radio halos and the effects on the galaxy radio emission. This book reviews our current understanding of cluster merging from an observational and theoretical perspective, and is appropriate for both graduate students and researchers in the field.

Cooling Flows in Clusters and Galaxies

Cooling Flows in Clusters and Galaxies PDF Author: A.C. Fabian
Publisher: Springer Science & Business Media
ISBN: 9400929536
Category : Science
Languages : en
Pages : 377

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Book Description
X-ray astronomers discovered the diffuse gas in clusters of galaxies about 20 years ago. It was later realized that the central gas density in some clusters, and in elliptical galaxies, is so high that radiative cooling is a significant energy loss. The cooling time of the gas decreases rapidly towards the centre of the cluster or galaxy and is less than a Hubble time within the innermost few hundred kiloparsecs. This results in a cooling flow in which the gas density rises in order to maintain pressure to support the weight of the overlying gas. The rate at which mass is deposited by the flow is inferred to be several hundreds of solar masses per year in some clusters. The fraction of clusters in which cooling flows are found may exceed 50 per cent. Small flows probably occur in most normal elliptical galaxies that are not in rich clusters. The implications of this simple phenomenon are profound, for we appear to be witnessing the ongoing formation of the central galaxy. In particular, since most of the gas is undetected once it cools below about 3 million K, it appears to form dark matter. There is no reason why it should be detectable with current techniques if each cooling proton only recombines once and the matter condenses into objects of low mass.

Clusters of Galaxies: Volume 3, Carnegie Observatories Astrophysics Series

Clusters of Galaxies: Volume 3, Carnegie Observatories Astrophysics Series PDF Author: John S. Mulchaey
Publisher: Cambridge University Press
ISBN: 9780521755771
Category : Science
Languages : en
Pages : 408

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Book Description
Series of review papers covering clusters of galaxies and related phenomena.