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Detailed studies of Damped and sub-Damped Lyman-alpha systems (DLA), the galaxies probed by the absorption they produce in the spectra of background quasars, rely on identifying the galaxy responsible for the absorber with more traditional…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Celine Peroux , Nicolas Bouche , Varsha P. Kulkarni , Donald G. York , Giovanni Vladilo

The XQ-100 survey has provided high signal-noise spectra of 100 redshift 3-4.5 quasars with the X-Shooter spectrograph. The metal abundances for 13 elements in the 41 damped Lyman alpha systems (DLAs) identified in the XQ-100 sample are…

The cosmic chemical enrichment as measured from damped Ly$\alpha$ absorbers (DLAs) will be underestimated if dusty and metal-rich absorbers have evaded identification. Here we report the discovery and present the spectroscopic observations…

Astrophysics of Galaxies · Physics 2018-07-25 K. E. Heintz , J. P. U. Fynbo , C. Ledoux , P. Jakobsson , P. Møller , L. Christensen , S. Geier , J. -K. Krogager , P. Noterdaeme

We have used the SEST 15-metre and Onsala 20-metre telescopes to perform deep (r.m.s. >~ 30 mJy) integrations of various molecular rotational transitions towards damped Lyman-alpha absorption systems (DLAs) known to occult millimetre-loud…

Astrophysics · Physics 2009-11-07 S. J. Curran , M. T. Murphy , J. K. Webb , F. Rantakyro , L. E. B. Johansson , S. Nikolic

We present arguments based on the measured abundances in individual damped Lyman alpha systems (DLAs) and sub-damped Lyman alpha systems (sub-DLAs), and also the average abundances inferred in large samples of QSO absorption line systems,…

We present a brief overview of the ongoing Complete Optical and Radio Absorption Line System (CORALS) survey. We review the results of our survey for z>2.2 damped Lyman alpha systems (DLAs) and present the preliminary results of an extended…

We present results from an efficient, non-traditional survey to discover damped Lyman-alpha (DLA) absorption-line systems with neutral hydrogen column densities N(HI)>2x10^{20} atoms cm^{-2} and redshifts z<1.65. Contrary to previous…

Astrophysics · Physics 2007-05-23 Sandhya Rao

We investigate the properties of damped Ly{\alpha} absorption systems (DLAs) in semi-analytic models of galaxy formation, including partitioning of cold gas in galactic discs into atomic, molecular, and ionized phases with a molecular…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Michael Berry , Rachel S. Somerville , Marcel R. Haas , Eric Gawiser , Ari Maller , Gergo Popping , Scott C. Trager

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…

With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar's environment in absorption. We search 149 moderate resolution background quasar spectra, from Gemini, Keck, the MMT,…

We report coincident damped Lyman alpha (DLA) and sub-DLA absorption at z = 2.66 and z = 2.94 towards the z ~ 3 13.8 arcsecond separation binary quasar SDSS 1116+4118 AB. At the redshifts of the absorbers, this angular separation…

Astrophysics · Physics 2009-06-23 Sara L. Ellison , Joseph F. Hennawi , Crystal L. Martin , Jesper Sommer-Larsen

We present VLT/UVES spectroscopy of the quasar Q0841+129, whose spectrum shows a proximate damped Lyman-alpha (PDLA) absorber at z=2.47621 and a proximate sub-DLA at z=2.50620, both lying close in redshift to the QSO itself at…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Andrew J. Fox , Cédric Ledoux , Patrick Petitjean , Raghunathan Srianand , Rodney Guimarães

The number of damped Ly-alpha absorbers (DLAs) currently known is about 100, but our knowledge of their sizes and morphologies is still very sparse as very few have been detected in emission. Here we present narrow-band and broad-band…

Astrophysics · Physics 2016-08-30 J. U. Fynbo , P. Moller , S. J. Warren

We report {\it HST} COS spectroscopy of 10 quasars with foreground star-forming galaxies at 0.02$<$$z$$<$ 0.14 within impact parameters of $\sim$1-7 kpc. We detect damped/sub-damped Ly$\alpha$ absorption in 100$\%$ of cases where no…

Le Brun et al. (1997) presented the first identifications of the galaxies giving rise to 7 intermediate redshift damped Ly-alpha (DLA) absorption systems. Here, we study the gravitational lensing properties of these foreground galaxies…

Astrophysics · Physics 2007-05-23 Vincent Le Brun , Alain Smette , Jean Surdej , Jean-Francois Claeskens

We have detected Lyman-alpha emission from a damped Lyman-alpha system (DLA) that lies near the bright quasar HS1549+1919. The DLA has the same redshift as HS1549+1919 and was discovered in the spectrum of a faint QSO that lies 49" away…

Astrophysics · Physics 2009-11-11 K. L. Adelberger , C. C. Steidel , J. A. Kollmeier , N. A. Reddy

(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

We present results from a survey of galaxies in the fields of six z>3 Damped Lyman alpha systems (DLAs) using the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT). We report a high detection rate of up to ~80% of…

We present results from a search for strong H2 absorption systems proximate to quasars (zabs~zem) in the Sloan Digital Sky Survey (SDSS) Data Release 14. The search is based on the Lyman-Werner band signature of damped H2 absorption lines…

Astrophysics of Galaxies · Physics 2019-07-03 P. Noterdaeme , S. Balashev , J. -K. Krogager , R. Srianand , H. Fathivavsari , P. Petitjean , C. Ledoux

We report the discovery of the first 'ghostly' damped Ly$\alpha$ absorption system (DLA), which is identified by the presence of absorption from strong low-ion species at $z_{\rm abs}=1.70465$ along the line of sight to the quasar…