Download or read book Constraints on Cluster Structure and Cosmology from X ray and Sunyaev Zel dovich Effect Properties of Galaxy Clusters written by Samuel J. Laroque and published by . This book was released on 2005 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Clusters of Galaxies Physics and Cosmology written by Andrei M. Bykov and published by Springer. This book was released on 2019-10-17 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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"
Download or read book 3K SN s Clusters Hunting the Cosmological Parameters with Precision Cosmology written by Domingos Barbosa and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: A JENAM 2002 Workshop, Porto, Portugal, 3-5 September 2002
Download or read book The Influence of Physical Processes in Galaxy Clusters on Observable Cluster Scaling Relations written by Hsiang-Yi Yang and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Clusters of galaxies, which occupy a unique position in hierarchical structure formation, are invaluable cosmological probes and laboratories for astrophysical processes. Cluster scaling relations, which connect their masses and observable properties, provide the link between these two roles. Cosmological constraints derived from cluster abundances often rely on calibrations or functional forms of these relations. On the other hand, the form and evolution of the mass-observable relations are affected by astrophysical processes during cluster formation. Understanding these processes not only provides insights into cluster physics but also has important implications for cluster cosmology. In this thesis, we use numerical simulations to study the influence of important physical mechanisms, including gravity, radiative cooling, and heating from active galactic nuclei (AGN), on cluster mass-observable relations. In particular, we investigate the physical origin of the intrinsic scatter around the best-fit relations by correlating it with measures of cluster structure, dynamical state, and AGN activity. Using a cosmological N -body plus hydrodynamic simulation produced using the FLASH code, we study the impact of cluster structure and dynamical state on the distribution of scatter in the X-ray temperature and Sunyaev-Zel0́9dovich (SZ) scaling relations. We also examine possible systematic biases in cluster cosmology, such as sample selection in cluster surveys, assumptions in self-calibration studies, and correlated errors in combining X-ray and SZ mass estimates. Correctly simulating cluster properties, especially inside cluster cores, requires additional baryonic physics, including radiative cooling and some heating mechanisms such as AGN feedback. However, because of the extreme dynamic range required to capture the rich physics involved in accretion onto and feedback by the supermassive black holes (SMBH) in AGN, current modeling of AGN in cosmological simulations is highly phenomenological and relies on heterogeneous parameterizations. We perform a systematic sensitivity study on a variety of these models and parameters and quantify the current theoretical uncertain- ties in the predicted cluster global quantities. This study is an important step toward the development of more robust AGN models within a cosmological framework.
Download or read book Questions of Modern Cosmology written by Mauro D'Onofrio and published by Springer Science & Business Media. This book was released on 2009-07-09 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Are we living in the "golden age" of cosmology? Are we close to understanding the nature of the unknown ingredients of the currently most accepted cosmological model and the physics of the early Universe? Or are we instead approaching a paradigm shift? What is dark matter and does it exist? How is it distributed around galaxies and clusters? Is the scientific community open to alternative ideas that may prompt a new scientific revolution - as the Copernican revolution did in Galileo's time? Do other types of supernovae exist that can be of interest for cosmology? Why have quasars never been effectively used as standard candles? Can you tell us about the scientific adventure of COBE? How does the extraction of the Cosmic Microwave Background anisotropy depend on the subtraction of the various astrophysical foregrounds? These, among many others, are the astrophysical, philosophical and sociological questions surrounding modern cosmology and the scientific community that Mauro D'Onofrio and Carlo Burigana pose to some of the most prominent cosmologists of our time. Triggered by these questions and in the spirit of Galileo's book "Dialogue Concerning the Two Chief World Systems" the roughly 40 interview partners reply in the form of essays, with a critical frankness not normally found in reviews, monographs or textbooks.
Download or read book Twelfth Marcel Grossmann Meeting The On Recent Developments In Theoretical And Experimental General Relativity Astrophysics And Relativistic Field Theories In 3 Volumes Proceedings Of The Mg12 Meeting On General Relativity written by Remo Ruffini and published by World Scientific. This book was released on 2012-02-02 with total page 2657 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marcel Grossmann Meetings are formed to further the development of General Relativity by promoting theoretical understanding in the fields of physics, mathematics, astronomy and astrophysics and to direct future technological, observational, and experimental efforts. In these meetings are discussed recent developments in classical and quantum gravity, general relativity and relativistic astrophysics, with major emphasis on mathematical foundations and physical predictions, with the main objective of gathering scientists from diverse backgrounds for deepening the understanding of spacetime structure and reviewing the status of test-experiments for Einstein's theory of gravitation. The range of topics is broad, going from the more abstract classical theory, quantum gravity and strings, to the more concrete relativistic astrophysics observations and modeling.The three volumes of the proceedings of MG12 give a broad view of all aspects of gravitational physics and astrophysics, from mathematical issues to recent observations and experiments. The scientific program of the meeting includes 29 plenary talks stretched over 6 mornings, and 74 parallel sessions over 5 afternoons. Volume A contains plenary and review talks ranging from the mathematical foundations of classical and quantum gravitational theories including recent developments in string theories, to precision tests of general relativity including progress towards the detection of gravitational waves, to relativistic astrophysics including such topics as gamma ray bursts, black hole physics both in our galaxy, in active galactic nuclei and in other galaxies, neutron stars, pulsar astrophysics, gravitational lensing effects, neutrino physics and ultra high energy cosmic rays. The rest of the volumes include parallel sessions on dark matter, neutrinos, X-ray sources, astrophysical black holes, neutron stars, binary systems, radiative transfer, accretion disks, alternative gravitational theories, perturbations of collapsed objects, analog models, black hole thermodynamics, cosmic background radiation & observational cosmology, numerical relativity & algebraic computing, gravitational lensing, variable ';constants'; of nature, large scale structure, topology of the universe, brane-world cosmology, early universe models & cosmic microwave background anisotropies, inhomogeneous cosmology, inflation, gamma ray burst modeling, supernovas, global structure, singularities, cosmic censorship, chaos, Einstein-Maxwell systems, inertial forces, gravitomagnetism, wormholes & time machines, exact solutions of Einstein's equations, gravitational waves, gravitational wave detectors & data analysis, precision gravitational measurements, history of relativity, quantum gravity & loop quantum gravity, Casimir effect, quantum cosmology, strings & branes, self-gravitating systems, gamma ray astronomy, cosmic rays, gamma ray bursts and quasars.
Download or read book Clusters of Galaxies Volume 3 Carnegie Observatories Astrophysics Series written by John S. Mulchaey and published by Cambridge University Press. This book was released on 2004-09-23 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Series of review papers covering clusters of galaxies and related phenomena.
Download or read book Galaxy Clusters written by Amruta J. Deshpande and published by . This book was released on 2016 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: I present studies of the X-ray emission from galaxy clusters in the context of understanding the multi-wavelength selection function and mass estimation of galaxy clusters. Clusters are gravitationally bound systems of dark matter, gas and galaxies, and are the largest gravitationally bound structures in the Universe. Constraining cosmology with cluster studies requires large, complete cluster samples with reliable masses over cosmologically significant survey volumes. Such samples are only just becoming available with new surveying telescopes that have optimal sensitivity for cluster finding, and some with the additionally useful property of finding clusters largely by their mass, which is the cosmologically significant cluster property. These surveys have increased the need for obtaining large, well-understood samples of clusters for characterizing their selection. Ongoing work in this field aims to determine the selection and limitations of the four ways of observing clusters and measuring their masses (optical/infrared, X-ray, weak lensing, or Sunyaev-Zel'dovich effect) using both large and small samples. In this context, I have studied small cluster samples in the X-ray and compared their properties to those determined through three different cluster selection methods: through weak lensing selection, optical selection, and selection through the Sunyaev-Zel'dovich effect. In this thesis I begin in the introduction with a brief overview of the current cosmological picture and how clusters help to constrain cosmology. In the subsequent chapters I describe my work in the X-ray, aimed at better understanding clusters selected through the different methods. I conclude with a summary of how my follow-up and other multi-wavelength studies have illuminated cluster selection and also with comments on the persisting need for similar studies in the near future.
Download or read book An Introduction to Distance Measurement in Astronomy written by Richard de Grijs and published by John Wiley & Sons. This book was released on 2011-09-26 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Distance determination is an essential technique in astronomy, and is briefly covered in most textbooks on astrophysics and cosmology. It is rarely covered as a coherent topic in its own right. When it is discussed the approach is frequently very dry, splitting the teaching into, for example, stars, galaxies and cosmologies, and as a consequence, books lack depth and are rarely comprehensive. Adopting a unique and engaging approach to the subject An Introduction to distance Measurement in Astronomy will take the reader on a journey from the solar neighbourhood to the edge of the Universe, discussing the range of distance measurements methods on the way. The book will focus on the physical processes discussing properties that underlie each method, rather than just presenting a collection of techniques. As well as providing the most compressive account of distance measurements to date, the book will use the common theme of distance measurement to impart basic concepts relevant to a wide variety of areas in astronomy/astrophysics. The book will provide an updated account of the progress made in a large number of subfields in astrophysics, leading to improved distance estimates particularly focusing on the underlying physics. Additionally it will illustrate the pitfalls in these areas and discuss the impact of the remaining uncertainties in the complete understanding of the Universes at large. As a result the book will not only provide a comprehensive study of distance measurement, but also include many recent advances in astrophysics.
Download or read book Precision Cosmology with Galaxy Cluster Surveys written by Hao-Yi Wu and published by Stanford University. This book was released on 2011 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: The acceleration of the universe, which is often attributed to "dark energy, " has posed one of the main challenges to fundamental physics. Galaxy clusters provide one of the most sensitive probes of dark energy because their abundance reflects the growth rate of large-scale structure and the expansion rate of the universe. Several large galaxy cluster surveys will soon provide tremendous statistical power to constrain the properties of dark energy; however, the constraining power of these surveys will be determined by how well systematic errors are controlled. Of these systematic errors, the dominant one comes from inferring cluster masses using observable signals of clusters, the so-called "observable--mass distribution." This thesis focuses on extracting dark energy information from forthcoming large galaxy cluster surveys, including how we maximize the cosmological information, how we control important systematics, and how precisely we need to calibrate theoretical models. We study how multi-wavelength follow-up observations can improve cluster mass calibration in optical surveys. We also investigate the impact of theoretical uncertainties in calibrating the spatial distributions of galaxy clusters on dark energy constraints. In addition, we explore how the formation history of galaxy clusters impacts the self-calibration of cluster mass. In addition, we use N-body simulations to develop a new statistical sample of cluster-size halos in order to further understand the observable--mass distribution. We study the completeness of subhalos in our cluster sample by comparing them with the satellite galaxies in the Sloan Digital Sky Survey. We also study how subhalo selections impact the inferred correlation between formation time and optical mass tracers, including cluster richness and velocity dispersion.
Download or read book Merging Processes in Galaxy Clusters written by L. Feretti and published by Springer Science & Business Media. This book was released on 2006-04-18 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book A Pan Chromatic View of Clusters of Galaxies and the Large Scale Structure written by Manolis Plionis and published by Springer. This book was released on 2008-02-17 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Soft X Ray Emission from Clusters of Galaxies and Related Phenomena written by R. Lieu and published by Springer Science & Business Media. This book was released on 2013-11-09 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the discovery of the cluster soft excess (CSE) over eight years ago, its properties and origin have been the subject of debate. With the recent launch of new missions such as XMM-Newton and FUSE, we are beginning to answer some of the complex issues regarding the phenomenon. This conference proceedings is an attempt to bring together the latest research results and covers both observational and theoretical work on the CSE and related topics. One of the main topics is the possible relationship between the CSE and the warm-hot intergalactic medium (WHIM), which is believed to harbor 50% of the baryons in the near Universe. New data from both XMM-Newton and FUSE have indicated a possible causal link between the WHIM and CSE. Evidence is based on the apparent detection of O VII emission lines in the soft excess spectrum of the outskirts of several clusters, as well as reports of absorption lines at local and higher redshifts (seen in the spectra of distant sources) as signature of the WHIM. However, while there has been considerable optimism in attributing a substantial fraction of the cluster soft excess flux to WHIM emission, other work shows that, for example, the amount of WHIM material predicted by theoretical simulations falls way short of that necessary to account for the CSE. Other work indicates that at the cores of some cluster this excess emission is so strong, it is impossible to invoke the thermal model without at the same time enlisting radically new physics. Thus alternative interpretations involving non-thermal processes are also reported and being pursued in earnest. Whatever the origin of CSE may turn out to be, results in this book show that it has become beyond reasonable doubt that the phenomenon itself is observationally established. This book reports the scientific progress made by bringing together scientists from a wide range of disciplines. It clearly demonstrates the importance of such meetings and participants if we are to solve this puzzle. This volume is aimed at scientists and graduate students in astronomy who want to learn about the latest results on cluster soft excess observations and theoretical implications.
Download or read book Multi scale Structure Formation and Dynamics in Cosmic Plasmas written by Andre Balogh and published by Springer. This book was released on 2016-02-02 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers eleven coordinated reviews on multi-scale structure formation in cosmic plasmas in the Universe. Observations and theories of plasma structures are presented in all relevant astrophysical contexts, from the Earth’s magnetosphere through heliospheric and galactic scales to clusters of galaxies and the large scale structure of the Universe. Basic processes in cosmic plasmas starting from electric currents and the helicity concept governing the dynamics of magnetic structures in planet magnetospheres, stellar winds, and relativistic plasma outflows like pulsar wind nebulae and Active Galactic Nuclei jets are covered. The multi-wavelength view from the radio to gamma-rays with modern high resolution telescopes discussed in the book reveals a beautiful and highly informative picture of both coherent and chaotic plasma structures tightly connected by strong mutual influence. The authors are all leading scientists in their fields, making this book an authoritative, up‐to‐date and enduring contribution to astrophysics.
Download or read book Groups of Galaxies in the Nearby Universe written by Ivo Saviane and published by Springer Science & Business Media. This book was released on 2007-08-01 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: For every galaxy in the field or in clusters, there are about three galaxies in groups. The Milky Way itself resides in a group. Groups in the local universe offer the chance to study galaxies in environments characterized by strong interactions. In the cosmological context, groups trace large-scale structures better than clusters; the evolution of groups and clusters appears to be related. All these aspects of research are summarized in this book.
Download or read book Weak Lensing by Galaxy Clusters written by and published by . This book was released on 2015 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: The story of the origin and evolution of our Universe is told, equivalently, by space-time itself and by the structures that grow inside of it. Clusters of galaxies are the frontier of bottom-up structure formation. They are the most massive objects to have collapsed at the present epoch. By that virtue, their abundance and structural parameters are highly sensitive to the composition and evolution of the Universe. The most common probe of cluster cosmology, abundance, uses samples of clusters selected by some observable. Applying a mass-observable relation (MOR), cosmological parameters can be constrained by comparing the sample to predicted cluster abundances as a function of observable and redshift. Arguably, however, cluster probes have not yet entered the era of per cent level precision cosmology. The primary reason for this is our imperfect understanding of the MORs. The overall normalization, the slope of mass vs. observable, the redshift evolution, and the degree and correlation of intrinsic scatters of observables at fixed mass have to be constrained for interpreting abundances correctly. Mass measurement of clusters by means of the differential deflection of light from background sources in their gravitational field, i.e. weak lensing, is a powerful approach for achieving this. This thesis presents new methods for and scientific results of weak lensing measurements of clusters of galaxies. The former include, on the data reduction side, (i) the correction of CCD images for non-linear effects due to the electric fields of accumulated charges (Chapter 2, Gruen et al. 2015a) and (ii) a method for masking artifact features in sets of overlapping images of the sky by comparison to the median image (Chapter 3, Gruen et al. 2014a). Also, (iii) I develop a method for the selection of background galaxy samples based on their color and apparent magnitude that includes a new correction for contamination with cluster member galaxies (Section 5.3.1). The main scientific results are the following. (i) For th! e Hubble Frontier Field cluster RXC J2248.7--4431 our lensing analysis constrains mass and concentration of the cluster halo and we confirm the large mass predicted by X-ray and Sunyaev-Zel'dovich (SZ) observations. The study of cluster members shows the relation of galaxy morphology to luminosity and environment (Chapter 4, Gruen et al. 2013). (ii) Our lensing mass measurements for 12 clusters are consistent with X-ray masses derived under the assumption of hydrostatic equilibrium of the intra-cluster gas. We confirm the MORs derived by the South Pole Telescope collaboration for the detection significance of the cluster SZ signal in their survey. We find discrepancies, however, with the Planck SZ MOR. We hypothesize that these are related either to a shallower slope of the MOR or a size, redshift or noise dependent bias in SZ signal extraction (Chapter 5, Gruen et al. 2014b). (iii) Finally, using a combination of simulations and theoretical models for the variation of cluster profiles at fixed mass, we find that the latter is a significant contribution to the uncertainty of cluster lensing mass measurements. A cosmic variance model, such as the one we develop, is necessary for MOR constraints to be accurate at the level required for future surveys (Chapter 6, Gruen et al. 2015b).
Download or read book Astronomy Cosmology and Fundamental Physics written by Peter A. Shaver and published by Springer Science & Business Media. This book was released on 2003-07-11 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an overview of many of the dramatic recent developments in the fields of astronomy, cosmology and fundamental physics. Topics include observations of the structure in the cosmic background radiation, evidence for an accelerating Universe, the extraordinary concordance in the fundamental parameters of the Universe coming from these and other diverse observations, the search for dark matter candidates, evidence for neutrino oscillations, space experiments on fundamental physics, and discoveries of extrasolar planets. This book will be useful for researchers and graduate students who wish to have a broad overview of the current developments in these fields.
