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In this first paper of a series, we report on the use of quasar spectra obtained with the UVES high resolution spectrograph and available through the ESO VLT archive to build the first sample of sub-DLA systems, absorbers with HI column…

Astrophysics · Physics 2009-11-10 M. Dessauges-Zavadsky , C. Peroux , T. -S. Kim , S. D'Odorico , R. G. McMahon

In an effort to study Damped Lyman Alpha galaxies at low redshift, we have been using the Sloan Digital Sky Survey to identify galaxies projected onto QSO sightlines and to characterize their optical properties. For low redshift galaxies,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Brian Cherinka , Regina Schulte-Ladbeck , Jessica Rosenberg

We study the H2 molecular content in high redshift damped Lyman-alpha systems (DLAs) as a function of the HI column density. We find a significant increase of the H2 molecular content around log N(HI) (cm^-2)~21.5-22, a regime unprobed…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-10 P. Noterdaeme , P. Petitjean , R. Srianand

We present the methodology for, and the first results from, a new imaging program aimed at identifying and characterizing the host galaxies of damped Lyman-alpha absorbers (DLAs) at z>2. We target quasar sightlines with multiple…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Michele Fumagalli , John M. O'Meara , J. Xavier Prochaska , Nissim Kanekar

We present a measurement of the HI column density distribution function, f(N), at the present epoch for column densities log N > 20 cm^-2. These high column densities compare to those measured in damped Ly alpha lines seen in absorption…

Astrophysics · Physics 2015-06-24 Martin Zwaan , Marc Verheijen , Frank Briggs

We are exploring the connection between damped Ly-alpha absorbers (DLAs) and Lyman break galaxies (LBGs) using deep -- (5sigma)=26 m_{AB}-- broad band imaging (UBVI) of four wide fields (0.25 sq. deg. each) obtained at the Kitt Peak 4-m…

Astrophysics · Physics 2007-05-23 Nicolas Bouche , James D. Lowenthal

Using a spectral stacking technique we searched for the average \lya emission from high-z Damped \lya (DLA) galaxies detected in the Sloan Digital Sky Survey QSO spectra. We used a sample of 341 DLAs of mean redshift <z>= 2.86 and log N(HI)…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 H. Rahmani , R. Srianand , P. Noterdaeme , P. Petitjean

Damped Ly$\alpha$ systems provide possibly the most significant evidence for early structure formation, and thus a stringent constraint on the Cold + Hot Dark Matter (CHDM) cosmology. Using the numbers of halos in N-body simulations to…

Astrophysics · Physics 2009-09-25 Anatoly Klypin , Stefano Borgani , Jon Holtzman , Joel Primack

(Abridged) We present the first results from the Complete Optical and Radio Absorption Line System (CORALS) survey. We have compiled a homogeneous sample of radio-selected QSOs from the Parkes Catalogue and searched for damped Lyman alpha…

Astrophysics · Physics 2009-11-07 Sara L. Ellison , Lin Yan , Isobel M. Hook , Max Pettini , Jasper V. Wall , Peter Shaver

In order to understand galaxy growth evolution, it is critical to constrain the evolution of its building block: gas. Mostly comprised by Hydrogen in its neutral (HI) and molecular (H2) phases, the latter is the one mostly directly…

Astrophysics of Galaxies · Physics 2024-02-12 Hugo Messias , Andrea Guerrero , Neil Nagar , Jack Regueiro , Violette Impellizzeri , Gustavo Orellana , Miguel Vioque

The correlation between neutral Hydrogen (HI) in the intergalactic medium (IGM) and galaxies now attracts great interests. We select four fields which include several coherently strong Ly$\alpha$ absorption systems at $z\sim2.2$ detected by…

We explore the redshift evolution of the metal content of damped Lyman alpha systems (DLAs) with new observations of four absorbers at z < 1.5 . The main conclusion is that the column density--weighted mean metallicity, [<Zn/H>] = -1.03 +/-…

Astrophysics · Physics 2009-10-30 Max Pettini , Sara L. Ellison , Charles C. Steidel , David V. Bowen

In order to interpret H2 (molecular hydrogen) quasar absorption line observations of damped Ly-alpha systems (DLAs) and sub-DLAs, we model their H2 abundance as a function of dust-to-gas ratio, including H2 self-shielding and dust…

Astrophysics · Physics 2009-11-10 H. Hirashita , A. Ferrara

We report a NOrthern Extended Millimeter Array (NOEMA) and Atacama Large Millimeter/submillimeter Array (ALMA) search for redshifted CO emission from the galaxies associated with seven high-metallicity ([M/H] $\geq -1.03$) damped…

This study presents results on detecting neutral atomic hydrogen (HI) 21cm absorption in the spectrum of PKS1413+135 at redshift $z=0.24670041$. The observation was conducted by FAST, with a spectral resolution of 10 Hz, using 10 minutes of…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-08 Jiangang Kang , Chang-Zhi Lu , TongJie Zhang , Ming Zhu

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…

Astrophysics · Physics 2009-11-07 Patrick Petitjean , R. Srianand , Cédric Ledoux

We report new HST and ground-based observations of a damped Lyman-alpha absorption system toward the QSO 0850+4400. The redshift of the absorption system is z = 0.163770 and the neutral hydrogen column density of the absorption system is…

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…

Astrophysics of Galaxies · Physics 2016-12-14 Ravi Joshi , Raghunathan Srianand , Pasquier Noterdaeme , Patrick Petitjean

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…

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