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 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 Cooling Flows in Clusters and Galaxies written by A.C. Fabian and published by Springer. This book was released on 1988-05-31 with total page 406 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 of Galaxies written by Patrick Koch and published by . This book was released on 1999 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Cooling Flows in Poor Clusters of Galaxies written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-28 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: We observed three poor clusters with central dominant galaxies (AWM 4, MKW 4, and MKW 3's) using the Position Sensitive Proportional Counter on the ROSAT X-ray satellite. The images reveal smooth, symmetrical X-ray emission filling the cluster with a sharp peak on each central galaxy. The cluster surface brightness profiles can be decomposed using superposed King models for the central galaxy and the intracluster medium. The King model parameters for the cluster portions are consistent with previous observations of these clusters. The newly measured King model parameters for the central galaxies are typical of the X-ray surface brightness distributions of isolated elliptical galaxies. Spatially resolved temperature measurements in annular rings throughout the clusters show a nearly isothermal profile. Temperatures are consistent with previously measured values, but are much better determined. There is no significant drop in temperature noted in the innermost bins where cooling flows are likely to be present, nor is any excess absorption by cold gas required. All cold gas columns are consistent with galactic foreground absorption. We derive mass profiles for the clusters assuming both isothermal temperature profiles and cooling flow models with constant mass flow rates. Our results are consistent with previous Einstein IPC observations by Kriss, Cioffi, & Canizares, but extend the mass profiles out to 1 Mpc in these poor clusters. Kriss, Gerard A. and Dillingham, Stephen Unspecified Center NAG5-1952...
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 Optical and X ray Studies of Cooling Flows in Clusters of Galaxies written by John Agrel Culver and published by . This book was released on 1983 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Simulation of Cooling Flows in Clusters of Galaxies written by Nasser Mohamed Ahmed and published by . This book was released on 2007 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Simulation of Cooling Flows in Clusters of Galaxies written by Nasser Mohamed Ahmed Mohamed Ismail and published by . This book was released on 2007 with total page 124 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 Galactic and Cluster Cooling Flows written by Noam Soker and published by . This book was released on 1997 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Cooling Flows and Cold Gas in Clusters of Galaxies written by Stuart Daines and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evidence for Cool Gas and Star Formation in Cluster Cooling Flows written by Brian Robert McNamara and published by . This book was released on 1991 with total page 356 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.
