相关论文: Extremely strong DLAs at high redshift: Gas coolin…

We present a study of the evolution of the column density distribution, f(N,z), and total neutral hydrogen mass in high-column density quasar absorbers using candidates from a recent high-redshift survey for damped Lyman-alpha (DLA) and…

We present here a dataset of quasars observed with the Ultraviolet Visual Echelle Spectrograph (UVES) on the VLT and available in the ESO UVES Advanced Data Products archive. The sample is made up of a total of 250 high resolution quasar…

We have identified a metal-strong (logN(Zn+) > 13.15 or logN(Si+) > 15.95) DLA (MSDLA) population from an automated quasar (QSO) absorber search in the Sloan Digital Sky Survey Data Release 3 (SDSS-DR3) quasar sample, and find that MSDLAs…

We study the average Ly$\alpha$ emission associated with high-$z$ strong (log $N$(H I) $\ge$ 21) damped Ly$\alpha$ systems (DLAs). We report Ly$\alpha$ luminosities ($L_{\rm Ly\alpha}$) for the full as well as various sub-samples based on…

The damped and sub-damped Lyman alpha systems (DLAs and sub-DLAs) traced in absorption against bright background quasars represent the main reserve of neutral hydrogen at high redshifts. We used the archival Very Large Telescope (VLT)…

We investigate a model for the high-ionization state gas associated with observed damped Lyman-alpha systems, based on a semi-analytic model of galaxy formation set within the paradigm of hierarchical structure formation. In our model, the…

We searched quasar spectra from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) for the rare occurrences where a strong damped Lyman-alpha absorber (DLA) blocks the Broad Line Region emission from the quasar and acts as a…

We study the dust depletion pattern in eight well separated components of the z=1.973, logN(HI)=20.83, damped Lyman-alpha system toward Q0013-004, four of which have detectable H2 absorption. The apparent correlation between the abundance…

Hubble Space Telescope (HST) UV spectroscopy of 12 candidate low-redshift damped Lyman alpha (DLA) systems in 11 QSOs (z=0.103 in Q0054+144, z=0.969 and z=0.987 in Q0302-223, z=0.478 in Q0454-220, z=1.476 in Q1047+550, z=1.070 in Q1206+459,…

We compare the properties of a sample of local (z=0) gas-rich galaxies studied in 21 cm emission to a sample of 13 low-redshift (z < 1) damped Lyman alpha (DLA) galaxies identified as the counterparts of low-redshift DLA systems found in…

We present a detailed analysis of a very unusual sub-damped Lyman alpha (sub-DLA) system at redshift z=2.304 towards the quasar Q0453-423, based on high signal-to-noise (S/N), high-resolution spectral data obtained with VLT/UVES. With a…

We have completed spectroscopic observations using LRIS on the Keck 1 telescope of 30 very high redshift quasars, 11 selected for the presence of damped Ly-alpha absorption systems and 19 with redshifts z > 3.5 not previously surveyed for…

To search for low-redshift damped Lyman-alpha (DLA) and sub-DLA quasar absorbers, we have conducted a 21cm absorption survey of radio-loud quasars at small impact parameters to foreground galaxies selected from the Sloan Digital Sky Survey…

Damped Lyman-{\alpha} Absorbers (DLAs) as a class of QSO absorption-line systems are currently our most important source of detailed information on the cosmic chemical evolution of galaxies. However, the degree to which this information is…

We present new elemental abundance studies of seven damped Lyman-alpha systems (DLAs). Together with the four DLAs analyzed in Dessauges-Zavadsky et al. (2004), we have a sample of eleven DLA galaxies with uniquely comprehensive and…

We use deep HST STIS and NICMOS images of three spectroscopically confirmed galaxy counterparts of high-redshift damped Ly-alpha (DLA) absorbers (one of which is a new discovery) to test the hypothesis that high-redshift DLA galaxies are…

We present the measured gas-phase metal column densities in 155 sub-damped Lyman alpha systems (subDLAs) with the aim to investigate the contribution of subDLAs to the chemical evolution of the Universe. The sample was identified within the…

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 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…

We present an ultraviolet spectroscopic survey of strong H I absorbers in the intergalactic medium, probing their evolution over the last 6-7 Gyr at redshifts $0.24 \leq z \leq 0.84$. We measure column densities $N_{\rm HI} \,( {\rm…