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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…

The similarity between observed velocity structures of Al III and singly ionised species in damped Lyman-alpha systems (DLAs) suggests the presence of ionised gas in the regions where most metal absorption lines are formed. To explore the…

Astrophysics · Physics 2009-10-31 Daniel Schaerer , Yuri Izotov , Corinne Charbonnel

In the $\Lambda$-CDM paradigm, the dark halo governs the gravitational potential within which a galaxy can form and evolve. In this Letter we show that the present-day inner ($r<50\text{ kpc}$) dark halo can be significantly misaligned with…

Astrophysics of Galaxies · Physics 2023-09-18 Jiwon Jesse Han , Vadim Semenov , Charlie Conroy , Lars Hernquist

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…

Astrophysics · Physics 2016-08-30 Sara L. Ellison , Max Pettini , Charles C. Steidel , Alice E. Shapley

Blind 21cm surveys in the local universe have shown that the local HI mass density, Omega_HI, is dominated by luminous, high surface brightness, spiral galaxies. On the other hand, surveys for host galaxies of damped Ly-alpha systems have…

Astrophysics · Physics 2007-05-23 Martin Zwaan , Frank Briggs , Marc Verheijen

We have investigated chemical evolution in the young universe by analysing the detailed chemical enrichment pattern of a metal-rich galaxy at high redshift. The recent detection of over 20 elements in the gas-phase of a damped Lyman-alpha…

Astrophysics · Physics 2009-11-10 Yeshe Fenner , Jason X. Prochaska , Brad K. Gibson

Determining the spatial distribution and intrinsic physical properties of neutral hydrogen on cosmological scales is one of the key goals of next-generation radio surveys. We use the EAGLE galaxy formation simulations to assess the…

We have measured the column density distribution function, f(N), at z=0 using 21-cm HI emission from galaxies selected from a blind HI survey. f(N) is found to be smaller and flatter at z=0 than indicated by high-redshift measurements of…

Astrophysics · Physics 2008-11-26 Emma Ryan-Weber , Rachel Webster , Lister Staveley-Smith

We present a low-redshift (z=0.029) Damped Lyman-alpha (DLA) system in the spectrum of a background Quasi-Stellar Object (QSO). The DLA is associated with an interacting galaxy pair within a galaxy group. We detected weak Lyman-alpha…

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…

Astrophysics · Physics 2009-11-07 M. Dessauges-Zavadsky , J. X. Prochaska , S. D'Odorico

Recent observations have revealed that damped Ly$\alpha$ clouds (DLAs) host star formation activity. In order to examine if such star formation activity can be triggered by ionization fronts, we perform high-resolution hydrodynamics and…

Astrophysics · Physics 2008-11-26 Ilian T. Iliev , Hiroyuki Hirashita , Andrea Ferrara

We test semi-analytic models for galaxy formation with accurate kinematic data of damped Lyman alpha protogalaxies (DLAs) presented in the companion paper I. The models envisage centrifugally supported exponential disks at the centers of…

Astrophysics · Physics 2009-10-31 Arthur M. Wolfe , Jason X. Prochaska

In 2000, we started the program ``Building the Bridge between Damped Ly-alpha Absorbers and Lyman-Break Galaxies: Ly-alpha Selection of Galaxies'' at the European Southern Observatory's Very Large Telescope. This project is an attempt to…

Astrophysics · Physics 2007-05-23 J. P. U. Fynbo , C. Ledoux , P. Moller , B. Thomsen , I. Burud , B. Leibundgut

Our understanding of the nature of DLA systems at large redshifts, ostensibly progenitors of normal disk galaxies, depends critically on their direct identifications with galaxies, and the resulting measurements of their properties. A few…

Astrophysics · Physics 2007-05-23 S. G. Djorgovski

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…

Astrophysics · Physics 2009-11-11 A. M. Hopkins , S. M. Rao , D. A. Turnshek

Measurements of Zn and Cr abundances in damped Lyman alpha systems at absorption redshifts between 0.692 and 3.390 show that metals and dust are much less abundant in high redshift galaxies than in the Milky Way today. We conclude that the…

Astrophysics · Physics 2009-10-28 Max Pettini , David L King , Linda J Smith , Richard W Hunstead

We present Giant Metrewave Radio Telescope HI 21cm absorption observations, of candidate and confirmed damped Lyman-$\alpha$ systems (DLAS). The derived spin temperatures (T_s) are in all cases $\sim 1000$ K or higher. We have also collated…

Astrophysics · Physics 2015-06-24 Jayaram N Chengalur , Nissim Kanekar

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)…

Astrophysics of Galaxies · Physics 2018-08-15 Waqas Bashir , Tayyaba Zafar , Fazeel M. Khan , Farrukh Chishtie

We have combined the results from our recent observations of Damped and sub-Damped Lyman-alpha systems with the MIKE and UVES spectrographs on the Magellan Clay and VLT Kueyen telescopes with ones from the literature to determine the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Joseph D. Meiring , James T. Lauroesch , Varsha P. Kulkarni , Celine Peroux , Pushpa Khare , Donald G. York

We present Cosmic Origins Spectrograph (COS) measurements of metal abundances in eight 0.083<z<0.321 damped Lyman-\alpha (DLA) and sub-damped Ly-\alpha\ absorption systems serendipitously discovered in the COS-Halos survey. We find that…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 A. J. Battisti , J. D. Meiring , T. M. Tripp , J. X. Prochaska , J. K. Werk , E. B. Jenkins , N. Lehner , J. Tumlinson , C. Thom