Related papers: Damped Lyman Alpha Systems and Galaxy Formation
Previously we have shown that it is possible to account for the kinematic properties of damped Lyman alpha systems (DLAS) in the context of semi-analytic models. In these models, hierarchical structure formation is approximated by…
We use numerical simulations of critically-closed cold dark matter (CDM) models to study the effects of numerical resolution on observable quantities. We study simulations with up to $256^3$ particles using the particle-mesh (PM) method and…
Assuming that damped Lyman-alpha(DLA) systems are galactic discs, we calculate the corresponding evolution of metal abundances. We use detailed multi-zone models of galactic chemical evolution (reproducing successfully the observed…
We present the results of a series of imaging and spectroscopic observations aimed at identifying and studying the galaxy responsible for the z = 3.38639 damped lya system in the z = 3.61 QSO Q0201+1120. We find that the DLA is part of a…
We present the first measurement of the large-scale cross-correlation of Lyman alpha forest absorption and Damped Lyman alpha systems (DLA), using the 9th Data Release of the Baryon Oscillation Spectroscopic Survey (BOSS). The…
We construct a simple, robust model of the chemical evolution of galaxies from high to low redshift, and apply it to published observations of damped Lyman-alpha quasar absorption line systems (DLAs). The elementary model assumes quiescent…
For almost two decades the properties of "dwarf" galaxies have challenged the Cold Dark Matter (CDM) paradigm of galaxy formation. Most observed dwarf galaxies consists of a rotating stellar disc embedded in a massive DM halo with a near…
We investigate structural properties of dark matter halos of disk galaxies in LCDM cosmology, using a well-defined sample of 81 disk-dominated galaxies from the SDSS redshift survey. We model the mass-velocity and fundamental plane…
The analysis of disk formation is based on the White & Rees (1978) picture, in which disk galaxies form by continuous cooling and accretion of gas within a merging hierarchy of dark matter halos. A simple Kennicutt law of star formation for…
In this paper we analyze a simple scenario in which Dark Matter (DM) consists of free fermions with mass $m_f$. We assume that on galactic scales these fermions are capable of forming a degenerate Fermi gas, in which stability against…
Though observationally rare, damped Lya absorption systems dominate the mass density of neutral gas in the Universe. Eleven high redshift damped Lya systems covering 2.8<z<4.4 were discovered in 26 QSOs from the APM z>4 QSO Survey,…
Quasars are the visible signatures of super-massive black holes in the centres of distant galaxies. It has been suggested that quasars are formed during ``major merger events'' when two massive galaxies collide and merge, leading to the…
We report new observations of ZnII and CrII absorption lines in 10 damped \lya systems (DLAs), mostly at redshift $z_{abs} \simgt 2.5$ . By combining these results with those from our earlier survey (Pettini et al. 1994) and other recent…
We report the detection of the host galaxy of a damped Ly$\alpha$ system (DLA) with log N(HI) $ [\rm cm^{-2}]$ = $21.0 \pm 0.10$ at $z \approx 3.0091$ towards the background quasar SDSS J011852+040644 using the Palomar Cosmic Web Imager…
Molecular hydrogen is quite underabundant in damped Lyman-alpha systems at high redshift, when compared to the interstellar medium near the Sun. This has been interpreted as implying that the gas in damped Lyman-alpha systems is warm. like…
We present results from a survey of galaxies in the fields of six z>3 Damped Lyman alpha systems (DLAs) using the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT). We report a high detection rate of up to ~80% of…
This paper constructs an analytic framework for calculating the assembly of galactic disks from the collapse of gas within dark matter halos, with the goal of determining the surface density profiles. Gas parcels (baryons) fall through the…
We use the semi-analytical approach to analyze gravitational lensing of quasars by dark halos in various cold dark matter (CDM) cosmologies, in order to determine the sensitivity of the prediction probabilities of images separations to the…
Galaxy formation depends critically on the physical state of gas in the circumgalactic medium (CGM) and its interface with the intergalactic medium (IGM), determined by the complex interplay between inflows from the IGM and outflows from…
We study the nature of damped Lya absorption (DLA) systems at z<=1 using a sample of 11 DLA galaxies, for which accurate redshift measurements are available. We demonstrate that the precision of photometric redshifts is sufficient for…