We compare new observations on the kinematic characteristics of the damped Lyα systems against results from numerical SPH simulations to test the predictions of hierarchical galaxy formation. This exercise is particularly motivated by recent numerical results on the cross-section of damped Lyα systems. Our analysis focuses on the velocity widths ∆v of ≈ 50 low-ion absorption profiles from our s...

We combine predictions for several hierarchical cosmogonies with observational evidence on damped Lyα systems to establish a correspondence between the high redshift galaxy population and the properties of damped Lyα systems (DLAS). We assume that high redshift galaxies and damped Lyα systems are hosted by the same dark matter halos and require consistency between the predicted halo space densi...

We present a comprehensive analysis of the damped Lyα abundance database presented in the first paper of this series. This database provides a homogeneous set of abundance measurements for many elements including Si, Cr, Ni, Zn, Fe, Al, S, Co, O, and Ar from 38 damped Lyα systems with zabs > 1.5. With little exception, these damped Lyα systems exhibit very similar relative abundances. There is ...

We present chemical abundance measurements for 19 damped Lyα systems observed with HIRES on the 10m W.M. Keck Telescope. We perform a detailed analysis of every system, deriving ionic column densities for all unblended metal-line transitions. Our principal goal is to investigate the abundance patterns of the damped systems and thereby determine the underlying physical processes which dominate t...

We investigate the heat source of the neutral gas comprising damped Ly systems. Unlike the Ly forest, where the extragalactic background radiation field ionizes and heats the gas, we find that grain photoelectric heating by the far-ultraviolet (FUV) background is not sufficient to balance the [C ii] 158 m cooling rate inferred from damped Ly systems where C ii absorption is detected. In these s...

In this work, we present an evolution of the DDS (Damped & Delayed Sinusoidal) model introduced within the framework of the general signal modeling. This model is named Partial Damped & Delayed Sinusoidal (PDDS) model and takes into account a single time delay parameter for a set of (un)damped sinusoids. This modification is more consistent with the transient audio modeling problem. Then, we de...

In the current research with novel first and second differentiations of a yield function, Euler forward along with Euler backward with its consistent elastic-plastic modulus are newly implemented in finite element program in rate-independent plasticity. An elastic-plastic internally pressurized thick walled cylinder is analyzed with four famous criteria including both pressure dependent and ind...

We prove some decay estimates of the energy of the wave equation governed by localized nonlinear dissipations in a bounded domain in which trapped rays may occur. The approach is based on a comparison with the linear damped wave equation and an interpolation argument. Our result extends to the nonlinear damped wave equation the well-known optimal logarithmic decay rate for the linear damped wav...

a tiling of a surface is a decomposition of the surface into pieces, i.e. tiles, which cover it without gaps or overlaps. in this paper some special polygonal tiling of sphere, ellipsoid, cylinder, and torus as the most abundant shapes of fullerenes are investigated.