26,878 research outputs found
Characterizing Galaxy Clusters with Gravitational Potential
We propose a simple estimator for the gravitational potential of cluster-size
halos using the temperature and density profiles of the intracluster gas based
on the assumptions of hydrostatic equilibrium and spherical symmetry. Using
high resolution cosmological simulations of galaxy clusters, we show that the
scaling relation between this estimator and the gravitational potential has a
small intrinsic scatter of ~8%-15%, and it is insensitive to baryon physics
outside the cluster core. The slope and the normalization of the scaling
relation vary weakly with redshift, and they are relatively independent of the
choice of radial range used and the dynamical states of the clusters. The
results presented here provide a possible way for using the cluster potential
function as an alternative to the cluster mass function in constraining
cosmology using galaxy clusters.Comment: 10 pages, 7 figures, 4 tables. Matching the version accepted for
publication in the Astrophysical Journa
Recommended from our members
Biomimetic Design and Fabrication of Interior Architecture of Tissue Scaffolds Using Solid Freeform Fabrication
Modeling, design and fabrication of tissue scaffolds with intricate architecture,
porosity and pore size for desired tissue properties presents a challenge in tissue engineering.
This paper will present the details of our development in designing and fabrication of the
interior architecture of scaffolds using a novel design approach. The Interior Architecture
Design (IAD) approach seeks to generate scaffold layered freeform fabrication tool path without
forming complicated 3D CAD scaffold models. This involves: applying the principle of layered
manufacturing to determine the scaffold individual layered process planes and layered contour;
defining the 2D characteristic patterns of the scaffold building blocks (unit cells) to form the
Interior Scaffold Pattern; and the generation of process tool path for freeform fabrication of
these scaffolds with the specified interior architecture. Feasibility studies applying the IAD
algorithm to example models and the generation of fabrication planning instructions will be
presented.Mechanical Engineerin
Group amenability properties for von Neumann algebras
In his study of amenable unitary representations, M. E. B. Bekka asked if
there is an analogue for such representations of the remarkable fixed-point
property for amenable groups. In this paper, we prove such a fixed-point
theorem in the more general context of a -amenable von Neumann algebra ,
where is a locally compact group acting on . The F{\o}lner conditions of
Connes and Bekka are extended to the case where is semifinite and admits a
faithful, semifinite, normal trace which is invariant under the action of
A simple image intensifying system for Berg-Barrett topography
A simple imaging system to facilitate crystal orientation with respect to the x−ray beam for Berg−Barrett topography has been constructed. This system consists of an image intensifier tube with an x−ray phosphor deposited on its fiber−optic input plate and means to manipulate and indicate the crystal orientation. Applications of the system to studies of both crystalline and biological samples are given
Modal analysis of high frequency acoustic signal approach for progressive failure monitoring in thin composite plates
During the past few decades, many successful research works have evidently shown remarkable capability of Acoustic Emission (AE) for early damage detection of composite materials. Modal Analysis of AE signals or Modal Acoustic Emission (MAE) offers a better theoretical background for acoustic emission analysis which is necessary to get more qualitative and quantitative result. In this paper, the application of MAE concept in a single channel AE source location detection method for failure characterization and monitoring in thin composite plates was presented. Single channel AE source location is one of the recent studies for composite early damage localization, owing to the growing interest and knowledge of modal analysis of AE wave. A tensile test was conducted for glass fiber epoxy resin specimen with small notch. A single channel of AE system was used to determine the AE source location on specimen under testing. The results revealed that AE single channel source location provides reasonable accuracy for glass fiber laminate which was tested
- …