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We present a new catalogue of Damped Lyman-$\alpha$ absorbers from SDSS DR16Q, as well as new estimates of their statistical properties. Our estimates are computed with the Gaussian process models presented in Garnett et al. (2017); Ho et…

Astrophysics of Galaxies · Physics 2021-08-24 Ming-Feng Ho , Simeon Bird , Roman Garnett

We have discovered molecular hydrogen in a fourth quasar damped Ly-alpha system (hereafter DLA). The UVES spectrograph on the 8.2m ESO Kueyen telescope has allowed the detection of H2 in gas with low metallicity, Z/Z_solar ~= 10^{-2}, and…

Astrophysics · Physics 2007-05-23 S. A. Levshakov , P. Molaro , M. Centurion , S. D'Odorico , P. Bonifacio , G. Vladilo

We present the first ever detection of Cobalt in a Damped Lyman Alpha system (DLA) at z = 1.92. In addition to providing important clues to the star formation history of these high redshift galaxies, we discuss how studying the Co abundance…

Astrophysics · Physics 2009-11-06 Sara L. Ellison , Sean G. Ryan , Jason X. Prochaska

Element abundances in high-redshift quasar absorbers offer excellent probes of the chemical enrichment of distant galaxies, and can constrain models for population III and early population II stars. Recent observations indicate that the…

Astrophysics of Galaxies · Physics 2016-10-26 Sean Morrison , Varsha P. Kulkarni , Debopam Som , Bryan DeMarcy , Samuel Quiret , Celine Peroux

We have identified galaxies near two quasars which are at the redshift of damped Lyman-alpha (DLA) systems in the UV spectra of the quasars. Both galaxies are actively forming stars. One galaxy has a luminosity close to the break in the…

We present the Damped Ly$\alpha$ Toolkit for automated detection and characterization of Damped Ly$\alpha$ absorbers (DLA) in quasar spectra. Our method uses quasar spectral templates with and without absorption from intervening DLAs to…

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…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-13 Ryan Cooke , Max Pettini , Charles C. Steidel

We present a spectroscopic study of six damped Lya absorption (DLA) systems at z<0.65, based on moderate-to-high resolution spectra of the galaxies responsible for the absorbers. Combining known metallicity measurements of the absorbers…

Astrophysics · Physics 2009-11-10 Hsiao-Wen Chen , Robert C. Kennicutt , Michael Rauch

We present the discovery of a low-redshift damped Ly$\alpha$ (DLA) system in the spectrum of background starburst galaxy SDSS J111323.88+293039.3 ($z=0.17514$). The DLA is at an impact parameter of $\rm \rho=36~kpc$ from the star forming…

We report a detection of the 9.7 micrometer silicate absorption feature in a damped Lyman-alpha (DLA) system at z_{abs} = 0.524 toward AO0235+164, using the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope. The feature shows…

Astrophysics · Physics 2009-06-23 Varsha P. Kulkarni , Donald G. York , Giovanni Vladilo , Daniel E. Welty

Observations of low mean metallicity of damped Lyman-alpha (DLA) quasar absorbers at all redshifts studied appear to contradict the predictions for the global mean interstellar metallicity in galaxies from cosmic chemical evolution models.…

Astrophysics · Physics 2009-05-29 V. P. Kulkarni , P. Khare , C. Peroux , D. G. York , J. T. Lauroesch , J. D. Meiring

We have used the Very Long Baseline Array to image 18 quasars with foreground damped Lyman-$\alpha$ systems (DLAs) at 327, 610 or 1420 MHz, to measure the covering factor $f$ of each DLA at or near its redshifted HI 21cm line frequency.…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 N. Kanekar , W. M. Lane , E. Momjian , F. H. Briggs , J. N. Chengalur

We present the detection of Ly-alpha, [OIII] and H-alpha emission associated with an extremely strong DLA system (N(HI) = 10^22.10 cm^-2) at z=2.207 towards the quasar SDSS J113520-001053. This is the largest HI column density ever measured…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 P. Noterdaeme , P. Laursen , P. Petitjean , S. D. Vergani , M. -J. Maureira , C. Ledoux , J. P. U. Fynbo , S. López , R. Srianand

We present Keck/HIRES abundance measurements and metal-line kinematic profiles of the damped Lyman alpha systems (DLAs) towards the quasars Q0933+733 (z_abs=1.479) and Q0948+433 (z_abs=1.233). These two DLAs have among the five highest HI…

Astrophysics · Physics 2009-11-10 Sandhya M. Rao , Jason X. Prochaska , J. Christopher Howk , Arthur M. Wolfe

We present a study of cold gas absorption from a damped Lyman-$\alpha$ absorber (DLA) at redshift $z_{\rm abs}=1.946$ towards two lensed images of the quasar J144254.78+405535.5 at redshift $z_{\rm QSO} = 2.590$. The physical separation of…

We report observations of four sub-damped Lyman-alpha (sub-DLA) quasar absorbers at z<0.5 obtained with the Hubble Space Telescope Cosmic Origins Spectrograph. We measure the available neutrals or ions of C, N, O, Si, P, S, Ar, Mn, Fe,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Debopam Som , Varsha P. Kulkarni , Joseph Meiring , Donald G. York , Celine Péroux , James T. Lauroesch , Monique C. Aller , Pushpa Khare

We use the Hubble Space Telescope (HST) archive of ultraviolet (UV) quasar spectroscopy to conduct the first blind survey for damped Ly-alpha absorbers (DLAs) at low redshift (z < 1.6). Our statistical sample includes 463 quasars with…

We present results of our HST Cycle 11 Survey for low-redshift (z<1.65) DLAs in the UV spectra of quasars selected from the SDSS Early Data Release. These quasars have strong intervening MgII-FeII systems which are known signatures of high…

Astrophysics · Physics 2009-11-13 Sandhya M. Rao , David A. Turnshek , Daniel. B. Nestor

We are undertaking an ALMA survey of molecular gas in galaxies selected for their strong HI absorption, so-called DLA/sub-DLA galaxies. Here we report CO(2-1) detection from a DLA galaxy at z = 0.716. We also present optical and…

We study the contents of an apparent void in the distribution of Ly-alpha emitting galaxies at redshift 2.38. We show that this void is not empty, but contains a damped Ly-alpha absorption-line system, seen in absorption against background…

Astrophysics · Physics 2009-11-11 L. E. H. Godfrey , P. J. Francis
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