Now showing items 1-10 of 45
Two-fluid atmosphere for relativistic stars
(IOP Publishing Ltd, 1999-04-01)
We have extended the Vaidya radiating metric to include both a radiation fluid and a string fluid. This paper expands our brief introduction to extensions of the Schwarzschild vacuum which appeared in 1998 Phys. Rev. D ...
A Morphology-Cosmology Connection for X-Ray-Clusters
(Univ Chicago Press, 1993-12-10)
We employ N-body/three-dimensional gasdynamic simulations of the formation of galaxy clusters to determine whether cluster X-ray morpholgies can be used as cosmological constraints. Confirming the analytic expectations of ...
On spherically symmetric cosmology in Riemann-Cartan spacetime with spin-density
(IOP Publishing Ltd, 1994-10-01)
We develop the average effective energy-momentum tensor for a spherically symmetric cosmology with randomly oriented spin using the improved energy-momentum tensor in the framework of the self-consistent Einstein-Cartan ...
Granite, a new very high energy gamma-ray telescope
(Elsevier, 1990-03)
A international collaboration of astrophysicists plan to construct a new 10-meter diameter gamma-ray Cerenkov telescope at the Whipple Observatory on Mt. Hopkins in Arizona. By operatin in coincidence with the original ...
Curvature and flatness in a Brans-Dicke universe
(Elsevier, 1994-06-27)
The evolution of a universe with Brans-Dicke gravity and nonzero curvature is investigated here. We find solutions to the equations of motion during the radiation dominated era. In a Friedman-Robertson-Walker cosmology we ...
The intracluster gas fraction in X-ray clusters: constraints on the clustered mass density
(Blackwell Science Ltd, 1997-12-01)
The mean intracluster gas fraction of X-ray clusters within their hydrostatic regions is derived from recent observational compilations of David, Jones & Forman and White & Fabian. At radii encompassing a mean density 500 ...
Energy conditions in non-Riemannian spacetimes
(Elsevier, 1994-12-26)
We interpret the energy conditions in non-Riemannian spacetimes by applying them to a family of stationary, axially symmetric solutions for the gravitational field equations for an Einstein-Cartan theory in a Riemann-Cartan ...
The effects of clumping and substructure on intracluster medium mass measurements
(Univ Chicago Press, 1999-07-20)
We examine an ensemble of 48 simulated clusters to determine the effects of small-scale density fluctuations and large-scale substructure on X-ray measurements of the intracluster medium (ICM) mass. We measure rms density ...
Nonlinear stationary waves and solitary waves in fluid systems with long-range forces
(Elsevier, 1993-11-15)
We study a class of nonlinear model equations which represent one-dimensional fluid systems with long range forces (such as gravity). We present elementary theorems which constrain the allowed types of stationary wave and ...
An X-ray size-temperature relation for galaxy clusters: Observation and simulation
(Univ Chicago Press, 1997-12-10)
We show that galaxy clusters conform to a tight relation between X-ray isophotal size R-I and emission-weighted intracluster medium (ICM) temperature [T-X]. The best-fit relation for 41 members of an X-ray flux-limited ...