Download or read book Studying Galaxy Clusters Through X rays and the Sunyaev Zel dovich Effect written by Miriam Elizabeth Ramos Ceja and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 X Ray Emission from Clusters of Galaxies written by Craig L. Sarazin and published by Cambridge University Press. This book was released on 1988-03-17 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: First published in 1988, this book is a comprehensive survey of the astrophysical characteristics of the hot gas which pervades clusters of galaxies. In our universe, clusters of galaxies are the largest organised structures. Typically they comprise hundreds of galaxies moving through a region of space ten million light years in diameter. The volume between the galaxies is filled with gas having a temperature of 100 million degrees. This material is a strong source of cosmic X-rays. Dr Sarazin describes the theoretical description of the origin, dynamics, and physical state of the cluster gas. Observations by radio and optical telescopes are also summarised. This account is addressed to professional astronomers and to graduate students. It is an exhaustive summary of a rapidly expanding field of research in modern astrophysics.
Download or read book Cosmological Aspects of X Ray Clusters of Galaxies written by W.C. Seitter and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NATO Advanced Study Institute "Cosmological Aspects of X-Ray Clus ters of Galaxies" took place in Vel en , Westphalia, Germany, from June 6 to June 18, 1993. It addressed the fruitful union of two topics, cosmology and X-ray clus ters, both of which carry substantial scientific weight at the beginning of the last decenium of the last century in the second millenium of our era. The so far largest X-ray "All-Sky Survey", observed by the ROSAT X-ray satel lite, and ROSAT's deep pointed observations, have considerably enlarged the base of X-ray astronomy, particularly concerning extragalactic sources. Cosmology has gained significant impetus from the large optical direct and spectroscopic surveys, based on high quality 2-dimensional receivers at large telescopes and powerful scan ning devices, harvesting the full information 1 content from the older technique of employing photographic plates. Radioastronomy and IR-astronomy with IRAS, as well as r-astronomy with GRO, continue and strengthen the role of extragalactic research. The rapidly growing computer power in data reduction and data storage facilities support the evolution towards large-number statistics. A most significant push was given to early cosmology by the needs of physics in trying to unravel the nature of forces which govern our material world. The topic of the ASI was chosen because it opens new vistas on this for ever new problem: the universe. Clusters of galaxies probe large-scale matter distributions and the structure of space-time.
Download or read book Analysis of Sunyaev Zel dovich Effect Mass observable Relations Using South Pole Telescope Observations of an X ray Selected Sample of Low mass Galaxy Clusters and Groups written by and published by . This book was released on 2015 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: We use microwave observations from the South Pole Telescope (SPT) to examine the Sunyaev-Zel'dovich effect (SZE) signatures of a sample of 46 X-ray selected groups and clusters drawn from ~6 deg2 of the XMM-Newton Blanco Cosmology Survey. These systems extend to redshift z = 1.02 and probe the SZE signal to the lowest X-ray luminosities (e"042 erg s-1) yet; these sample characteristics make this analysis complementary to previous studies. We develop an analysis tool, using X-ray luminosity as a mass proxy, to extract selection-bias-corrected constraints on the SZE significance and Y_500 mass relations. The former is in good agreement with an extrapolation of the relation obtained from high-mass clusters. However, the latter, at low masses, while in good agreement with the extrapolation from the high-mass SPT clusters, is in tension at 2.8[sigma] with the Planck constraints, indicating the low-mass systems exhibit lower SZE signatures in the SPT data. We also present an analysis of potential sources of contamination. For the radio galaxy point source population, we find 18 of our systems have 843 MHz Sydney University Molonglo Sky Survey sources within 2 arcmin of the X-ray centre, and three of these are also detected at significance>4 by SPT. Of these three, two are associated with the group brightest cluster galaxies, and the third is likely an unassociated quasar candidate. We examine the impact of these point sources on our SZE scaling relation analyses and find no evidence of biases. We also examine the impact of dusty galaxies using constraints from the 220 GHz data. The stacked sample provides 2.8[sigma] significant evidence of dusty galaxy flux, which would correspond to an average underestimate of the SPT Y_500 signal that is (17 ± 9)per cent in this sample of low-mass systems. Finally, we explore the impact of future data from SPTpol and XMM-XXL, showing that it will lead to a factor of 4 to 5 tighter constraints on these SZE mass-observable relations.
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 X ray Studies of the Central Engine in Active Galactic Nuclei with Suzaku written by Hirofumi Noda and published by Springer. This book was released on 2015-12-07 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this research was to use the X-ray satellite Suzaku to establish a picture of a central engine that effectively converts the gravitational energy of accreting matter onto the supermassive black hole to a huge amount of radiation in an active galactic nucleus. Although the engine is known to consist of a Comptonizing corona and an accretion disk, its image has remained unclear because primary emissions, coming directly from the engine, cannot be identified in X-ray spectra without models. The book describes a technique of time variability assisted spectral decomposition to model-independently examine X-ray signals, and how this was applied to the Suzaku archive data of active galactic nuclei. As a result, at least three distinct primary X-ray components have been discovered in an X-ray from an active galactic nucleus, presumably indicating a novel picture that the engine is composed of multiple coronae with different physical properties in an accretion flow. Furthermore, the determination of the spectral shapes of the primary X-rays has a significant impact on estimations of black hole spins, because it is essential to quantify reprocessed X-ray spectra. The successful model-independent decomposition of X-ray spectral components with flux variations of active galactic nuclei is likely to be effective in future data analyses from the soon-to-be-launched Japanese X-ray satellite ASTRO-H, which is capable of achieving unprecedented fine spectros copy and broad energy band coverage.
Download or read book Clusters of Galaxies written by William R. Oegerle and published by Cambridge University Press. This book was released on 1990 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collected in this volume are the review papers from the Space Telescope Science Institute symposium on Clusters of Galaxies held in May 1989. Fifteen experts in the field have presented summaries of our current understanding of the formation and evolution of clusters and their constituent galaxies. Subjects covered include the existence and importance of subclustering, models of the evolution of clusters and the intracluster medium, the effect of the cluster environment on galaxies, observations of high redshift clusters, and the use of clusters as tracers of large scale structure. This book provides a timely focus for future observational and theoretical work on clusters of galaxies.
Download or read book Cosmological Studies of the Sunyaev Zel dovich Effect with the APEX SZ Instrument written by Jared Joseph Mehl and published by . This book was released on 2009 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cygnus A Study of a Radio Galaxy written by C. L. Carilli and published by Cambridge University Press. This book was released on 1996-02-29 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive and up-to-date review of Cygnus A and what it can teach us about other active galaxies - for graduate students and researchers.
Download or read book Outskirts of Galaxy Clusters IAU C195 written by International Astronomical Union. Colloquium and published by Cambridge University Press. This book was released on 2004-12-16 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the proceedings of the International Astronomical Union Colloquium no. 195, held in Torino, Italy in 2004. The meeting investigated the formation of galaxies within a full cosmological context, focusing on the outer regions of galaxy clusters. The observed correlation of optical and radio properties of galaxies with their environment indicates that the formation and evolution of galaxies is intimately linked to the formation of large scale structure. With chapters written by leading authorities in the field, this timely volume investigates the role of the environment in determining the properties of galaxies. It describes the distribution of matter and galaxies on the largest scales in the Universe, the processes of cluster and galaxy formation, their role and interplay. This is a valuable collection of review articles for professional astronomers.
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 Clusters of Galaxies written by Florence Durret and published by Atlantica Séguier Frontières. This book was released on 1994 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Vision Of An Old Cluster A Untangling Coma Berenices written by Alain Mazure and published by World Scientific. This book was released on 1998-08-15 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Together with Virgo, the Coma Berenices cluster is one of the most well-studied clusters at all wavelengths and in all aspects, from the Sunyaev-Zeldovich effect to star formation in galaxies. In a way, it is the prototype of rich clusters. Recent observational results, linked to the improvement of techniques such as X-ray and UV observations, along with multi-object spectroscopy, have shown that they could change our vision of this cluster. It is thus time for observers and theoreticians to confront all these new ideas and observations on the Coma cluster.The topics in this volume include: cosmological aspects of the Coma cluster, comparison with distant clusters; substructures; matter content and distribution; Sunyaev-Zeldovich effect; dynamical modelling, cluster dynamics; environmental effects on galaxies, star formation.
Download or read book Instrumentation and Analysis for Observations of the Sunyaev Zel dovich Effect from Galaxy Clusters with the APEX SZ Experiment written by James Kennedy and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Clusters of galaxies are the largest gravitationally bound objects in the Universe. Their size makes them unique and powerful tools for cosmology and the study of astrophysical processes. The hot gas that resides between the galaxies constitutes the majority of the baryonic matter in the cluster, and can be detected through its emission processes as well as its effect on the cosmic microwave background (CMB) radiation in a process known as the Sunyaev-Zel'dovich effect (SZE).This thesis describes the Atacama Pathfinder EXperiment Sunyaev-Zel'dovich (APEX-SZ) project. This experiment was the first large-array TES bolometer instrument and observed galaxy clusters through the SZE. APEX-SZ employed 280 TES detectors and operated for 875 hours over five years, making targeted observations of 42 galaxy clusters. The scientific motivation for the APEX-SZ experiment is given, along with a description of the general instrumentation for a large-array TES bolometer receiver. In addition, an electronic temperature readout and control board, developed at McGill and operated by multiple CMB experiments, is presented. The data calibration and analysis of the APEX-SZ data is discussed, along with the SZE measurements from galaxy clusters and their scaling-relations with X-ray data." --
Download or read book Handbook of X ray and Gamma ray Astrophysics written by Cosimo Bambi and published by Springer Nature. This book was released on with total page 5912 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Clusters and Superclusters of Galaxies written by A.C. Fabian and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
