相关论文: A simple analytical model for the abundance of dam…
Lyman limit and damped Lyman-alpha absorption systems probe the distribution of collapsed, cold gas at high redshift. Numerical simulations that incorporate gravity and gas dynamics can predict the abundance of such absorbers in…
We calculate the number of damped Lyman-alpha absorbers expected in various popular cosmological models as a function of redshift and compare our predictions with observed abundances. The Press-Schechter formalism is used to obtain the…
We examine the constraints on theories of galaxy formation that are obtained from observations of damped $\lya$ (DL) systems, assuming they are gaseous protodisks in dark matter halos. Using the Press-Schechter formalism, we find that the…
A model of damped lyman alpha systems is presented based on randomly moving clouds in spherical halos. We use the Press-Schechter model for the abundance of halos, and assume that each halo has a similar population of clouds, with total…
Any viable cosmological model must produce enough structure at early epochs to explain the amount of gas associated with high-redshift damped Ly$\alpha$ systems. We study the evolution of damped Ly$\alpha$ systems at redshifts $z\ge 2$ in…
There is accumulating observational evidence suggesting that damped Ly$\alpha$ absorption systems systems are the progenitors of present-day spiral galaxies. We use the observed properties of these systems to place constraints on the…
We develop a simple analytic model for the gravitational clustering of dark matter haloes to understand how their spatial distribution is biased relative to that of the mass. The statistical distribution of dark haloes within the initial…
We have made a detailed comparison of the results of large N-body simulations with the analytical description of the merging histories of dark matter halos presented in Lacey & Cole 1993, which is based on an extension of the Press-…
Structure formation provides a strong test of any cosmic acceleration model because a successful dark energy model must not inhibit {\black or overpredict} the development of observed large-scale structures. Traditional approaches to…
Using the GAEA semi-analytic model, we analyse the connection between Damped Lyman-$\alpha$ systems (DLAs) and HI in galaxies. Our state-of-the-art semi-analytic model is tuned to reproduce the local galaxy HI mass function, and that also…
We investigate the properties of damped Ly{\alpha} absorption systems (DLAs) in semi-analytic models of galaxy formation, including partitioning of cold gas in galactic discs into atomic, molecular, and ionized phases with a molecular…
We study halo mass functions with the Press-Schechter formalism for interacting dark matter models, where matter power spectra are damped due to dark acoustic oscillations in the early universe. After adopting a smooth window function, we…
We use cosmological smoothed-particle hydrodynamics (SPH) simulations of the Lambda cold dark matter (CDM) model to study the abundance of damped Lyman-alpha absorbers (DLAs) in the redshift range z=0-4.5. We compute the cumulative DLA…
We employ observationally determined intrinsic velocity widths and column densities of damped Lyman-alpha systems at high redshift to investigate the distribution of baryons in protogalaxies within the context of a standard cold dark matter…
Damped Ly$\alpha$ systems provide possibly the most significant evidence for early structure formation, and thus a stringent constraint on the Cold + Hot Dark Matter (CHDM) cosmology. Using the numbers of halos in N-body simulations to…
We derive an estimate of the rate of formation of dark matter halos per unit volume as a function of the halo mass and redshift of formation. Analytical estimates of the number density of dark matter halos are useful in modeling several…
Reservoirs of dense atomic gas (primarily hydrogen), contain approximately 90 percent of the neutral gas at a redshift of 3, and contribute to 2-3 percent of the total baryons in the Universe. These damped Lyman-${\alpha}$ systems (so…
In order to interpret H2 (molecular hydrogen) quasar absorption line observations of damped Ly-alpha systems (DLAs) and sub-DLAs, we model their H2 abundance as a function of dust-to-gas ratio, including H2 self-shielding and dust…
Damped Lyman-alpha systems (DLAs) are useful probes of star formation and galaxy formation at high redshift. We study the physical properties of DLAs and their relationship to Lyman-break galaxies using cosmological hydrodynamic simulations…
We use the extended Press-Schechter formalism to investigate the rate at which cold dark matter haloes accrete mass. We discuss the shortcomings of previous methods that have been used to compute the mass accretion histories of dark matter…