Full Description
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.
Contents
The Cluster Soft Excess.- The Extreme Ultraviolet Excess Emission in Five Clusters of Galaxies Revisited.- Soft (1 KEV) X-Ray Emission in Galaxy Clusters.- A Massive Halo of Warm Baryons in the Coma Cluster.- Soft X-Ray Excess Emission in Three Clusters of Galaxies Observed with XMM-Newton.- XMM-Newton Discovery of O VII Emission from Warm Gas in Clusters of Galaxies.- XMM-Newton Discovery of an X-Ray Filament in Coma.- The Cluster Abell 85 and its X-ray Filament Revisited by Chandra and XMM-Newton.- Absorption Line Studies of out Galaxy and the Whim.- Chandra Detection of X-ray Absorption from Local Warm/Hot Gas.- The Fuse Survey of O VI in the Galactic Halo.- The Fuse Survey of High Velocity O VI in the Vicinity of the Milky Way.- Ionization of High Velocity Clouds in the Galactic Halo.- Soft X-Ray Data Analysis Issues.- The Ism from the Soft X-ray Background Perspective.- Peering Through the Muck: Notes on the Influence of the Galactic Interstellar Medium on Extragalactic Observations.- Hard X-Ray Excesses and Non-Thermal Processes.- Hard X-Ray Excesses in Clusters of Galaxies and Their Non-Thermal Origin.- Thermal and Non-Thermal SZ Effect in Galaxy Clusters.- What the SZ Effect Can Tell us About the Electron Populations in the Coma Cluster.- Theoretical Models of Clusters, the CSE and the Whim.- Observational Constraints on Models for the Cluster Soft Excess Emission.- High-Resolution Simulations of Clusters of Galaxies.- Whim Emission and the Cluster Soft Excess: A Model Comparison.- New Instrumentation and the Future.- Observing the Warm-Hot Intergalactic Medium with Xeus.
