Download or read book Multi wavelength Observations of Galaxy Clusters written by Thomas Patrick Connor and published by . This book was released on 2016 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Multiwavelength Atlas of Galaxies written by Glen Mackie and published by Cambridge University Press. This book was released on 2011-01-06 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the radio signature of our own Milky Way was detected in 1931, galaxies have been observed from ultra-high energy gamma rays to long wavelength radio waves, providing fundamental insights into their formation, evolution and structural components. Unveiling the secrets of some of the best-observed galaxies, this atlas contains over 250 full-color images spanning the whole electromagnetic spectrum. The accompanying text explains why we see the component stars, gas and dust through different radiation processes, and describes the telescopes and instruments used. This atlas is a valuable reference resource on galaxies for students seeking an overview of multiwavelength observations and what they tell us, and researchers needing detailed summaries of individual galaxies. An accompanying website, hosted by the author, contains slide shows of the galaxies covered in the book. This is available at www.cambridge.org/9780521620628.

Download or read book Multi wavelength Observations of Spiral Galaxies in Clusters of Galaxies written by Gregory David Bothun and published by . This book was released on 1981 with total page 978 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 2020-10-31 with total page 535 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 Heating versus Cooling in Galaxies and Clusters of Galaxies written by Hans Böhringer and published by Springer Science & Business Media. This book was released on 2007-09-27 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume documents recent developments that have advanced our understanding of the heating and cooling mechanisms in galaxies and galaxy clusters. Chapters detail results from multi-wavelength observations and advances in numerical hydrodynamical simulations. An additional section covers new research findings on feedback and self-regulatory mechanisms during cosmic structure formation in general and in galaxy formation in particular.

Download or read book Multiwavelength Cosmology written by Manolis Plionis and published by Springer Science & Business Media. This book was released on 2006-04-18 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent scientific efforts in Astrophysics & Cosmology have brought a revolution to our understanding of the Cosmos. Amazing results is the outcome of amazing experiments! The huge scientific, technological & financial effort that has gone into building the 10-m class telescopes as well as many space and balloon observatories, essential to observe the multitude of cosmic phenomena in their manifestations at different wavelengths, from gamma-rays to the millimetre and the radio, has given and is still giving its fruits of knowledge. These recent scientific achievements in Observational and Theoretical Cosmology were presented in the "Multiwavelength Cosmology" conference that took place on beautiful Mykonos island in the Aegean between 17 and 20 June 2003. More than 180 Cosmologists from all over the world gathered for a four-day intense meeting in which recent results from large ground based surveys (AAT/2-df, SLOAN) and space missions (WMAP, Chandra, XMM, ISO, HST) were presented and debated, providing a huge impetus to our knowledge of the Cosmos. The future of the subject (experiments, and directions of research) was also discussed. The conference was devoted mostly on the constraints on Cosmological models and galaxy formation theories that arise from the study of the high redshift Universe, from clusters of galaxies, and their evolution, from the cosmic microwave background, the large-scale structure and star-formation history.

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 Measuring the Growth of Structure with Multi wavelength Surveys of Galaxy Clusters written by and published by . This book was released on 2008 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current and near-future galaxy cluster surveys at a variety of wavelengths are expected to provide a promising way to obtain precision measurements of the growth of structure over cosmic time. This in turn would serve as an important precision probe of cosmology. However, to realize the full potential of these surveys, systematic uncertainties arising from, for example, cluster mass estimates and sample selection must be well understood. This work follows several different approaches towards alleviating these uncertainties. Cluster sample selection is investigated in the context of arcminute-resolution millimeter-wavelength surveys such as the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT). Large-area, realistic simulations of the microwave sky are constructed and cluster detection is simulated using a multi-frequency Wiener filter to separate the galaxy clusters, via their Sunyaev-Zel'dovich signal, from other contaminating microwave signals. Using this technique, an ACT-like survey can expect to obtain a cluster sample that is 90% complete and 85% pure above a mass of 3 x 10^14 Msun. Cluster mass uncertainties are explored by comparing X-ray and weak-lensing mass estimates for shear-selected galaxy clusters in the Deep Lens Survey (DLS) to study possible biases in using cluster baryons or weak-lensing shear as tracers of the cluster total mass. Results are presented for four galaxy clusters that comprise the top-ranked shear-selected system in the DLS, and for three of these clusters there is agreement between X-ray and weak-lensing mass estimates. For the fourth cluster, the X-ray mass estimate is higher than that from weak-lensing by 2-sigma, and X-ray images suggest this cluster may be undergoing a merger with a smaller cluster, which may be biasing the X-ray mass estimate high. The feasibility of measuring galaxy cluster peculiar velocities using an ACT-like instrument is also investigated. Such a possibility would allow one to measure structure growth via large-scale velocity fields and circumvent the uncertainties associated with measuring cluster masses. We show that such measurements are possible and yield statistical uncertainties of roughly 100 km/sec given either a temperature prior with 1-sigma errors of less than 2 keV or additional lower frequency millimeter-band observations.

Download or read book Cosmology with Clusters of Galaxies written by Sandor Mihaly Molnar and published by Nova Science Publishers. This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive review of the methods applied to derive cosmological parameters for a given model and test different cosmological models using the most massive collapsed structures in our Universe: clusters of galaxies. Clusters typically consist of hundreds of galaxies and high-temperature ionised gas trapped in their gravitational field dominated by dark matter extending out to 2-3 Mpc. The formation, evolution, and structure of these massive rare objects are sensitive probes of the assumed cosmology. This is a multidisciplinary field of astrophysics involving multi-wavelength observations, gravity theory, atomic physics, plasma physics, magneto-hydrodynamics, astrophysical cosmology and numerical simulations. Our understanding of the physics of clusters, which is essential when using them for cosmology, has been improved tremendously due to the recent advent of technology and observational strategy in multi-frequency observations, and enhanced by improved numerical simulations made possible by more advanced high performance computers. As a result of these developments, cosmology with clusters of galaxies has become a mature discipline recently, and provided an important contribution to establish our concordance cosmological constant dominated cold dark matter model. In the near future we expect a rapid expansion of this field due to results from new cluster surveys and multi-wavelength observations. This timely volume on this exciting newly established field discusses galaxy cluster physics and provides a detailed description of using clusters to derive cosmological parameters applying accurate measurements of individual clusters as well as using clusters as a statistical tool. A detailed discussion is given on degeneracies between derived parameters and the systematic effects, which are becoming a limiting factor. An account for using clusters to test different cosmological models is also presented. This volume provides an introduction to galaxy cluster cosmology for physics and astronomy graduate students and serves as a reference source for professionals.

Download or read book A Multi wavelength Study of Galaxy Clusters Hosting Radio Sources written by Joshua David Wing and published by . This book was released on 2013 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Galaxy clusters play an important role in understanding the formation of structure in the Universe and can be used to constrain cosmological parameters. Thousands of clusters are known in the nearby Universe, but few are confirmed at large distances. Remote clusters provide a view of the early Universe, and are important for studying galaxy evolution. Here, I describe a technique for finding distant clusters using bent, double-lobed radio galaxies. These radio sources are active galactic nuclei (AGN) that result from outflows of material surrounding supermassive black holes in the centers of massive galaxies. These outflows are typically bent as a result of the relative motion between the host galaxy and the surrounding hot gas that fills clusters. Using the Sloan Digital Sky Survey (SDSS) and the Faint Images of the Radio Sky at Twenty-centimeters ( FIRST ) survey, I determine the frequency with which bent radio sources are associated with rich galaxy clusters in the nearby Universe (z 0.5), as compared to non-bent radio sources. I find that 60% of bent radio sources are located in rich cluster environments, compared to 10 - 20% of non-bent radio sources. Therefore, bent radio sources are efficient tracers for clusters and are useful as beacons of clusters at large distances. Bent radio sources may achieve their morphologies through large-scale cluster mergers that set the intracluster medium (ICM) in motion. Using a suite of substructure tests, I determine the significance of optical substructure in clusters containing radio sources. I find no preference for substructure in clusters with bent double-lobed sources compared to other types of radio sources, indicating that bent sources will not necessarily preferentially select clusters undergoing recent large-scale mergers. Having established that bent radio sources efficiently locate clusters, I have obtained deep, follow-up observations at optical and near-infrared wavelengths to uncover associated distant cluster candidates. In addition, a large Spitzer Space Telescope survey is underway to observe all bent sources not detected in the SDSS. Follow-up observations reveal a large number of high-redshift candidates. Further study of these objects will lend insight into galaxy formation and evolution and feedback between an AGN and its environment at high-redshift for clusters with a range of masses.

Download or read book A Multi wavelength Study of Optically Selected Galaxy Clusters from the Blanco Cosmology Survey written by Lindsey Ellen Bleem and published by . This book was released on 2013 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abundance measurements of galaxy clusters provide powerful constraints of cosmology. The observed distribution of clusters can potentially be used to disentangle whether the accelerated cosmic expansion can be explained by a modification to Einstein's theory of gravity or whether the explanation involves a new form of 'dark' energy. Such growth of structure measurements are both complementary to and provide an important cross-check of measurements of the geometry of the universe. There are two key requirements for cosmology with galaxy clusters: a census of these systems through cosmic time and the ability to connect the measured signal with the underlying mass of the galaxy cluster. In this era of large-area millimeter and optical wavelength surveys (including the South Pole Telescope (SPT) 2500-square-degree SZ-Survey and the Dark Energy Survey (DES)) where hundreds (mm-wave) to hundreds of thousands (optical) of clusters will be detected, the most serious limitation to cluster cosmology remains understanding and calibrating observable-mass relations. Combining cluster observables across wavelengths can both test and inform our knowledge of such scaling relations. As a pilot program for future explorations of the combined SPT and DES datasets, we explore the relation between the optical-richness, lambda, and SZ-signal for a sample of 567 optically-selected clusters from the Blanco Cosmology Survey, an ~ 80 square-degree survey located within the SPT-SZ survey. In this study we detect SZ-signal at increasing significance as a function of cluster richness but find that the recovered signal falls below expectations derived from models based on X-ray samples. We explore possible biases to our recovered signal and find that contamination from cluster members -- in particular radio and dust emission from galaxies--is small and that the majority of the discrepancy at the high mass end can be explained by errors in identifying the optical centers of clusters. The toolset developed here can be combined with future cluster catalogs from the Dark Energy Survey to help improve mass-richness scaling relations and ultimately constrain cosmological models.

Download or read book Multiwavelength Observations of Clusters of Galaxies and the Role of Cluster Mergers written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Some clusters of galaxies have been identified as powerful sources of non-thermal radiation, from the radio to X-ray wavelengths. The classical models proposed for the explanation of this radiation usually require large energy densities in cosmic rays in the intracluster medium and magnetic fields much lower than those measured using the Faraday rotation. They study here the role that mergers of clusters of galaxies may play in the generation of the non-thermal radiation, and they seek for additional observable consequences of the model. They find that if hard X-rays and radio radiation are respectively interpreted as inverse Compton scattering (ICS) and synchrotron emission of relativistic electrons, large gamma ray fluxes are produced, and for the Coma cluster, where upper limits are available, these limits are exceeded. They also discuss an alternative and testable model that naturally solves the problems mentioned above.

Download or read book Multi wavelength Emissions from Dark Matter Annihilation Processes in Galaxy Clusters Using Cosmological Simulations written by Remudin Reshid Mekuria and published by . This book was released on 2017 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Multi wavelength Observations of Nearby Active Galaxies written by Anthony John Holloway and published by . This book was released on 1996 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Multi wavelength Study of Galaxy Cluster Cores written by Victoria Helena Hamilton-Morris and published by . This book was released on 2011 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Horizons from Multi Wavelength Sky Surveys written by Brian J. McLean and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large area sky surveys are now a reality in the radio, IR, optical and X-ray passbands. In the next few years, new surveys using optical, UV and IR mosaic cameras with high throughput digital detectors will expand the dynamic range and accuracy of photometry and astrometry of objects over a significant fraction of the entire sky. Parallel X-ray and radio surveys over the same areas will produce astronomical image and spectroscopic databases of unprecedented size and quality. The combined data sets will provide significant new constraints on star formation, stellar dynamics, Galactic structure, the evolution of galaxies and large scale structure, as well as new opportunities to identify rare objects in the solar system and the Galaxy. Large area surveys have formidable data acquisition, processing, archiving, and data distribution demands and this meeting provided a forum for sharing experiences amongst workers specializing in different wavebands as well as discussing how multiband observations can reveal fundamental relationships in our understanding of the Universe.