相关论文: The Metallicity Evolution of Damped Lyman-alpha Sy…
We present a galactic chemical evolution model which adopts updated prescriptions for all the main processes governing the dust cycle. We follow in detail the evolution of the abundances of several chemical species (C, O, S, Si, Fe and Zn)…
We report the discovery and analysis of the most metal-poor damped Lyman-alpha (DLA) system currently known, based on observations made with the Keck HIRES spectrograph. The metal paucity of this system has only permitted the determination…
We have combined new high resolution UVES-VLT observations of a sample of four damped Ly-alpha systems (DLAs) at redshifts between z_abs = 1.7-2.5 with the existing HIRES-Keck spectra to undertake a comprehensive study of their physical…
Nitrogen abundances have been derived in Damped Ly alpha (DLA) galaxies at Zabs = 2.309, 2.827 and 3.025 toward the QSOs 0100+1300, 1425+6039 and 0347-3819 respectively. The behaviour of nitrogen relative to iron-peak and alpha-elements has…
We present HIRES observations for 30 damped Lyman alpha systems, selected on the basis of their large metal column densities from previous, lower resolution data. The measured metal column densities for Fe, Zn, S, Si, Cr, Mn, and Ni are…
The Damped and sub-Damped Lyman-alpha (DLA and sub-DLA) systems seen in the spectra of QSOs offer a unique way to study the interstellar medium of high redshift galaxies. In this paper we report on new abundance determinations in a sample…
The Circum-Galactic Medium (CGM) can be probed through the analysis of absorbing systems in the line-of-sight to bright background quasars. We present measurements of the metallicity of a new sample of 15 sub-damped Lyman-$\alpha$ absorbers…
We investigate the population of z=3 damped Lyman alpha absorbers (DLAs) in a recent series of high resolution galaxy formation simulations. The simulations are of interest because they form at z=0 some of the most realistic disk galaxies…
We test the hypothesis that the host galaxies of long-duration gamma-ray bursts (GRBs) as well as quasar-selected damped Lyman-alpha (DLA) systems are drawn from the population of UV-selected star-forming, high-z galaxies (generally…
Using the Atacama Large Millimeter/sub-millimeter Array, we have detected CO(3-2) line and far-infrared continuum emission from a galaxy associated with a high-metallicity ([M/H] = -0.27) damped Ly-alpha absorber (DLA) at z =2.19289. The…
High redshift DLA systems suggest that the relative abundances of elements might be roughly solar, although with absolute abundances of more than two orders of magnitude below solar. The result comes from observations of the [SII/ZnII]…
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…
The results of a new spectroscopic survey of 66 $z \simgt 4$ quasars for Damped Lyman-alpha absorption systems are presented. The search led to the discovery of 30 new DLA candidates which are analysed in order to compute the comoving mass…
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 present a model for the Lyman-alpha absorbers that treats all objects (from the low-density forest clouds to the dense damped systems) in a unified description. This approach is consistent with an earlier model of galaxies (luminosity…
By means of detailed chemical evolution models for galaxies of different morphological types (i.e. spirals, irregular/starburst galaxies and ellipticals) we study the nature of Damped Lyman-Alpha systems. Our concern is to infer which…
We measure a relation between the depth of four prominent rest-UV absorption complexes and metallicity for local galaxies and verify it up to z~3. We then apply this relation to a sample of 224 galaxies at 3.5 < z < 6.0 (<z> = 4.8) in…
We present chemical abundance measurements in the z_abs=3.35045 Damped Lyman-alpha (DLA) system observed in the UVES spectrum of the BAL quasar BR 1117-1329. We measure a neutral hydrogen column density N(HI)=6.9+/-1.7*10^{20} atoms/cm2 and…
The local power law relationship between the surface densities of neutral hydrogen gas and star formation rate (SFR) can be used to explore the SFR properties of damped Lyman alpha (DLA) systems at higher redshift. We find that while the…
I review a technique for interpreting faint galaxy data which traces the evolution with cosmic time of the galaxy luminosity density, as determined from several deep spectroscopic samples and the HDF. The method relies on the rest frame UV…