相关论文: The Metallicity Evolution of Damped Lyman-alpha Sy…

Recent chemical abundance measurements of damped Ly-alpha absorbers (DLAs) revealed an intrinsic scatter in their metallicity of ~0.5 dex out to z~5. In order to explore the origin of this scatter, we build a semi-analytic model which…

We analyse a sample of 24 damped Lyman-alpha (DLA)/moderate DLA systems at 0.3<z<2.2, all with measurement of the weak MnII absorption lines, to investigate which elemental ratios could possibly be used as tracers of either dust depletion…

We investigate some basic properties of Damped Lyman alpha systems based on the Semi-Analytical model of disk galaxy formation theory. We derive the DLA metallicity, column density, number density, gas content and cosmic star formation rate…

Based on the disk galaxy formation theory within the framework of standard LCDM hierarchical picture, we selected modelled DLAs, according to their observational criterion, by Monte Carlo simulation with the random inclinations being…

We estimate the abundance of dust in damped Lyman-{\alpha} absorbers (DLAs) by statistically measuring the excess reddening they induce on their background quasars. We detect systematic reddening behind DLA consistent with the SMC type…

We present a study of the early build-up of dust in high redshift galaxies. The study is based on the analysis of 38 Damped Ly alpha systems (DLAs) for which we derive the fraction of iron atoms in dust form, f_{Fe}. The sample is…

We present elemental abundance measurements for 9 damped Ly-alpha systems (DLAs) and 1 sub-DLA at 0.1 < z < 1.5 from recent observations with the Multiple Mirror Telescope. Most of these absorbers are found to be metal-poor, while 2 are…

Damped Lyman-alpha absorbers (DLAs), seen in absorption against a background quasar, provide the most detailed probes available of element abundances in the Universe over > 90 % of its age. DLAs can be used to observationally measure the…

Relative elemental abundances, and in particular the alpha/Fe ratio, are an important diagnostic tool of the chemical evolution of damped Ly alpha systems (DLAs). The S/Zn ratio is not affected by differential dust depletion and is an…

We consider the questions of whether the damped Lyman-alpha (DLA) and sub-DLA absorbers in quasar spectra differ intrinsically in metallicity, and whether they could arise in galaxies of different masses. Using the recent measurements of…

We study metal depletion due to dust in the interstellar medium (ISM) to infer the properties of dust grains and characterize the metal and dust content of galaxies, down to low metallicity and intermediate redshift z. We provide metal…

A scaling relation has recently been suggested to combine the galaxy mass-metallicity (MZ) relation with metallicities of damped Lyman-alpha systems (DLAs) in quasar spectra. Based on this relation the stellar masses of the absorbing…

Using the redshift evolution of the neutral hydrogen density, as inferred from observations of damped Ly$\alpha$ clouds, we calculate the evolution of star formation rates and elemental abundances in the universe. For most observables our…

We analyze the redshift evolution of the mass-metallicity relation in a sample of 110 Damped Ly$\alpha$ absorbers spanning the redshift range $z=0.11-5.06$ and find that the zero-point of the correlation changes significantly with redshift.…

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…

Using a sample of 100 H I - selected damped Lyman alpha (DLA) systems, observed with the High Resolution Echelle Spectrometer on the Keck I telescope, we present evidence that the scatter in the well-studied correlation between the redshift…

We estimate the intrinsic neutral gas density in Damped Lyman Alpha systems ($\Omega_{HI}^{(DLA)}$) in the redshift range $ 2.2 \lesssim z \lesssim 5$ from the DLA SDSS DR_3 sample of optically selected quasars. We take into account…

Damped Ly-alpha Systems (DLAs), with N(HI)>2*10^20 cm^{-2}, observed in quasars have allowed us to quantify the chemical content of the Universe over cosmological scales. Such studies can be extended to lower N(HI), in the sub-DLA range…

Observations of evolution in the dust-to-metal ratio allow us to constrain the dominant dust processing mechanisms. In this work, we present a study of the dust-to-metal and dust-to-gas ratios in a sub-sample of ~500 DustPedia galaxies.…

Context. Several issues regarding the nature of dust at high redshift remain unresolved: its composition, its production and growth mechanisms, and its effect on background sources. Aims. We provide a more accurate relation between dust…