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Related papers: The SDSS Damped Lya Survey: Data Release 3

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We present the results from an automated search for damped Lya (DLA) systems in the quasar spectra of Data Release 1 from the Sloan Digital Sky Survey (SDSS-DR1). At z~2.5, this homogeneous dataset has greater statistical significance than…

Astrophysics · Physics 2015-06-24 Jason X. Prochaska , Stephane Herbert-Fort

We present the results of a survey for damped (DLA, log N(H I) > 20.3) and sub-damped Lyman-? systems (19.5 < log N(H I) < 20.3) at z > 2.55 along the lines-of-sight to 77 quasars with emission redshifts in the range 4 < zem < 6.3.…

We present the first results from an ongoing survey for Damped Lyman-alpha systems (DLAs) in the spectra of z>2 quasars observed in the course of the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of the Sloan Digital Sky…

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 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 present new estimates for the statistical properties of damped Lyman-$\alpha$ absorbers (DLAs). We compute the column density distribution function at $z>2$, the line density, $\mathrm{d}N/\mathrm{d}X$, and the neutral hydrogen density,…

Astrophysics of Galaxies · Physics 2017-01-25 Simeon Bird , Roman Garnett , Shirley Ho

We present the results of a search for damped Lyman-alpha (DLA) systems in the Sloan Digital Sky Survey II (SDSS), Data Release 7. We use a fully automatic procedure to identify DLAs and derive their column densities. The procedure is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 P. Noterdaeme , P. Petitjean , C. Ledoux , R. Srianand

We report new observations of ZnII and CrII absorption lines in 10 damped \lya systems (DLAs), mostly at redshift $z_{abs} \simgt 2.5$ . By combining these results with those from our earlier survey (Pettini et al. 1994) and other recent…

Astrophysics · Physics 2015-06-24 Max Pettini , Linda J. Smith , David L. King , Richard W. Hunstead

We derive the statistical properties of neutral gas at redshifts 0.11<z<1.65 from UV measurements of quasar Lyman alpha absorption lines corresponding to 369 MgII systems with $W^{\lambda2796}_{0} \ge 0.3$ \AA. In addition to the 41 damped…

Astrophysics of Galaxies · Physics 2017-08-23 Sandhya M. Rao , David A. Turnshek , Gendith M. Sardane , Eric M. Monier

Using the Sloan Digital Sky Survey, Data Release 5, we survey proximate damped Lya systems (PDLAs): absorption line systems with HI column density N(HI)> 2x10^20 cm^{-2} at velocity separation dv < 3000 km/s from their background quasar.…

Astrophysics · Physics 2009-11-13 Jason X. Prochaska , Joseph F. Hennawi , Stephane Herbert-Fort

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

We present new results on the frequency distribution of projected HI column densities f(N,X), total comoving covering fraction, and integrated mass densities rho_HI of high redshift, HI `disks' from a survey of damped Lya systems (DLAs) in…

Astrophysics · Physics 2009-11-13 J. Xavier Prochaska , Arthur M. Wolfe

We present a study of ~100 high redshift (z~2-4) extremely strong damped Lyman-alpha systems (ESDLA, with N(HI)>0.5x10^22 cm^-2) detected in quasar spectra from the Baryon Oscillation Spectroscopic Survey SDSS-III DR11. We study the neutral…

Astrophysics of Galaxies · Physics 2014-07-01 P. Noterdaeme , P. Petitjean , I. Paris , Z. Cai , H. Finley , J. Ge , M. M. Pieri , D. G. York

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…

Astrophysics · Physics 2008-11-26 Kentaro Nagamine

A comprehensive analysis of 355 high-quality WSRT HI 21-cm line maps of nearby galaxies shows that the properties and incident rate of Damped Lyman-alpha (DLA) absorption systems observed in the spectra of high redshift QSOs are in good…

We present a sample of 38 intervening Damped Lyman $\alpha$ (DLA) systems identified towards 100 $z>3.5$ quasars, observed during the XQ-100 survey. The XQ-100 DLA sample is combined with major DLA surveys in the literature. The final…

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

The history and progress of DLA research over the past several decades is reviewed here. Larger datasets and deeper surveys, particularly over the last couple of years, have improved our knowledge of the neutral gas content and distribution…

Astrophysics · Physics 2009-11-11 Sandhya M. Rao

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…

Astrophysics · Physics 2009-11-06 Celine Peroux , Richard G. McMahon , Lisa J. Storrie-Lombardi , Mike J. Irwin

We have examined some basic properties of damped Ly$\alpha$ systems(DLAs) by semi-analytic model. We assume that DLA hosts are disk galaxies whose mass function is generated by Press-Schechter formulism at redshift 3. Star formation and…

Astrophysics · Physics 2008-11-26 J. L. Hou , C. G. Shu , S. Y. Shen , R. X. Chang
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