Download or read book Gas Flow in Galaxies and Clusters written by James Christopher Baker and published by . This book was released on 1976 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cooling Flows in Clusters and Galaxies written by A.C. Fabian and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Cooling Flows in Clusters and Galaxies written by A C Fabian and published by . This book was released on 1988-05-31 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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.
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 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 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 The Physical Characteristics of the X ray Emitting Gas in Clusters of Galaxies and Constraints on Dark Matter written by Mark Jeffrey Henriksen and published by . This book was released on 1985 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 The Interaction of Gas and Galaxies Within Galaxy Clusters written by Jill Cornell Tarter and published by . This book was released on 1975 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Matter and Energy in Clusters of Galaxies written by Stuart C. Bowyer and published by . This book was released on 2003 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Spectral Constraints on Models of Gas in Clusters of Galaxies written by Mark J. Henriksen and published by . This book was released on 1985 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measuring Mass written by Ricardo Zánmar Sánchez and published by . This book was released on 2009 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is concerned with the motions of gas in disk galaxies and with the motions of stars in a globular cluster to learn about their mass content. First we study non-circular streaming motions of HI gas in five representative disk galaxies with a bisymmetric model. We show that this physically motivated method can represent a wide range of bar-like distortions and that its model parameters can be related to useful physical parameters of galaxies like the amplitude of the forced non-circular speed, the bar angle, and the halo ellipticity. We also model the non-circular gas flow in the strongly barred galaxy NGC~1365. The gravitational potential is based on new observations that include photometric imaging, Fabry-Perot emission line imaging spectroscopy and a detailed re-analysis of archival HI data from the VLA. We use our 2-dimensional velocity map to constrain the strength and positions of the shocks in hydrodynamical simulations and find that better agreement is found with a massive, but not fully maximal disk $(m{M/L}simeq 2.0pm 1.0)$ and a fast bar (corotation at 1.2$m{R_{bar}}$). The analysis was complicated by the discovery of an asymmetric distribution of dust and kinematics in the bar region despite the remarkably bisymmetric distribution of the I-band light. We have measured 543 radial velocities of stars in the direction of the Galactic globular cluster M80 with Fabry-Perot absorption-line imaging spectroscopy. The data is used to derive the total mean velocity of $7.39 pm 0.54$ kms, the total velocity dispersion of $10.1 pm 0.4$ kms, a declining dispersion profile, and the rotation of the cluster. M80 is rotating with an amplitude of $2.42 pm 0.81$ kms along an axis with a position angle of $246.1degr pm 17.1$ (measured from North through East), which is perpendicular to the major axis of the cluster flattening. We have fitted single- and multi-mass Michie-King models to our velocity data and to surface-brightness profiles taken from the literature. Only when we increase the expected present-day number of white dwarfs are we able to match the expected $M/L_V$ of the stellar population with the dynamically-derived value of $3.0pm0.3$. We tentatively interpret this as evidence of tidal stripping given that M80 is on an orbit that keeps it in the inner regions of the Galaxy and therefore has probably experienced significant tidal mass loss.
Download or read book Cooling Flows in Clusters of Galaxies written by Avery Abraham Meiksin and published by . This book was released on 1988 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Properties of the Gas in Early type Galaxies and Galaxy Clusters written by Rachel L.S. Frisbie and published by . This book was released on 2020 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the baryons, or "normal" matter, found in galaxies and galaxy clusters are found in the hot, X-ray emitting gas known as the circumgalactic medium (CGM) or intracluster medium (ICM). The hot gas traces the gravitational potential well and is affected by both thermal and gravitational processes, so we use observations of the hot gas to explore changes across the galaxy or cluster's radius. Heating and cooling in the central regions of galaxies and clusters is primarily driven by feedback processes, including Active Galactic Nuclei (AGNs) and Type Ia supernovae. We can use X-ray observations of the hot gas to understand its thermal history and how the various feedback mechanisms affect the gas at small and large radii. Furthermore, we use X-ray gas properties (temperature, density, entropy, concentration, centroid shift, and power ratios) to characterize galaxies and clusters, understand their evolution, and classify them in meaningful ways. The combination of observations along with theoretical models and simulations explored in this thesis provides key insight into understanding how feedback processes affect the hot gas.I begin by presenting gas property results for a uniformly reduced sample of 348 galaxy clusters and show how those results can be used to characterize the sample and for further galaxy cluster science. I will then turn my focus to early-type galaxies for the remainder of this work. I examine a sample of 12 nearby early-type galaxies with powerful radio sources and find that IC 4296 exhibits unusually low central entropy as previously observed in NGC 4261. We also find some evidence that the minimum of the ratio between the cooling time and free-fall time, if it occurs at the galaxy center, may indicate the presence of a powerful radio source. Finally, I examine the galactic atmospheres of a sample of 49 early-type galaxies. I will show that the equilibrium pressure and density radial profiles for single- and multiphase galaxies agree with the Voit et al. (2020) theoretical model. I also find evidence for a correlation between the central velocity dispersion and entropy profile slope of the galaxies in the sample that agrees with the theoretical model.
