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The chemical abundances in damped Lyman-alpha systems (DLAs) show more than 2 orders of magnitude variation at a given epoch, possibly because DLAs arise in a wide variety of host galaxies. This could significantly bias estimates of…

Astrophysics · Physics 2007-05-23 M. T. Murphy , S. J. Curran , J. K. Webb

The hypothesis that the Damped Ly-alpha systems (DLAs) are large, galactic disks (Milky Way sized) is tested by confronting predictions of models of the formation and evolution of (large) disk galaxies with observations, in particular the…

Astrophysics · Physics 2009-10-31 Jesper Sommer-Larsen

We look for signs of the H~I transverse proximity effect in the spectra of 130 QSO pairs, most with transverse separations in the plane of the sky of 0.1 -- 3 Mpc at z ~ 2.2. We expected to see a decrease in Lyman-alpha forest HI absorption…

Astrophysics · Physics 2009-11-13 David Kirkman , David Tytler

We describe the properties of the Ly$\alpha$ forest in the column density range $\nhi \geq 2\times10^{12}$ cm$^{-2}$ based on 1056 lines in the wavelength range 4300--5100\AA measured in extremely high S/N, $R=36,000$ spectra of four…

Astrophysics · Physics 2009-10-28 Esther M. Hu , Tae-Sun Kim , Lennox L. Cowie , Antoinette Songaila , Michael Rauch

We use state of the art hydrodyamical simulations from the Sherwood, EAGLE and Illustris projects to examine the signature of $M_{\rm z=0}\simeq 10^{14}M_{\odot}$ protoclusters observed in Ly-$\alpha$ absorption at $z\simeq 2.4$. We find…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-13 Joel S. A. Miller , James S. Bolton , Nina Hatch

(Abridged) I investigate statistical properties of one-dimensional fields in the universe such as the Lyman alpha forest and inverted line-of-sight densities. Because of gravitational clustering, the cosmic density field is already quite…

Astrophysics · Physics 2007-05-23 Hu Zhan

We have performed a multi-species hydrodynamical simulation of the formation and evolution of Lyman alpha clouds in a flat CDM dominated universe with an external flux of ionizing radiation. We solve the fully coupled non-equilibrium rate…

Astrophysics · Physics 2009-10-28 Yu Zhang , Peter Anninos , Michael L. Norman

Spectroscopic observations of distant quasars have resulted in the detection of molecular hydrogen in intervening damped Lyman-alpha absorption clouds (DLAs). We use observations compiled from different experimental groups to show that the…

Astrophysics · Physics 2009-11-10 Stephen J. Curran , John K. Webb , Michael T. Murphy , Robert F. Carswell

We investigate correlations between the long wavelength fluctuations and the small scale power in the Lyman alpha forest. We show that such correlations can be used to discriminate between fluctuations induced by large scale structure and…

Astrophysics · Physics 2009-10-31 Matias Zaldarriaga , Uros Seljak , Lam Hui

It has recently become possible to measure directly the abundances of several chemical elements in a variety of environments at redshifts up to z = 5. In this review I summarise the latest observations of Lyman break galaxies, damped Lyman…

Astrophysics · Physics 2009-10-31 Max Pettini

We report the discovery of two damped Ly-alpha absorption-line systems (DLAs) near redshift z=1 along a single quasar sightline (Q1727+5302) with neutral hydrogen column densities of N(HI) = (1.45\pm0.15)\times10^{21} and…

We study the transverse clustering properties of high matter density peaks as traced by high column density absorption systems (either Lyman limit systems characterized by N(HI)> 2 x 10^{17} cm^{-2} or CIV systems with W_{r}> 0.5 A) at…

Astrophysics · Physics 2010-04-06 Valentina D'Odorico , Patrick Petitjean , Stefano Cristiani

The hydrogen Ly$\alpha$ forest is an important probe of the $z>2$ Universe that is otherwise challenging to observe with galaxy redshift surveys, but this technique has traditionally been limited to 1D studies in front of bright quasars.…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Khee-Gan Lee

We use a cosmological hydrodynamic simulation of a cold dark matter universe to investigate theoretically the relationship between high redshift galaxies and the Lyman=alpha forest at redshift z=3. Galaxies in the simulation are surrounded…

We investigate how damped Lyman-$\alpha$ absorbers (DLAs) at z ~ 2-3, detected in large optical spectroscopic surveys of quasars, trace the population of star-forming galaxies. Building on previous results, we construct a model based on…

Astrophysics of Galaxies · Physics 2020-05-27 J. -K. Krogager , P. Møller , L. B. Christensen , P. Noterdaeme , J. P. U. Fynbo , W. Freudling

We study the distribution of low-redshift Ly$\alpha$ clouds in a CDM model using numerical simulations including photoionization and cooling of the baryonic component. The ionizing background is found to be efficient enough to keep most of…

Astrophysics · Physics 2016-08-30 Patrick Petitjean , Jan P. Mücket , Ron Kates

We present predictions for the one-point probability distribution and cumulants of the transmitted QSO flux in the high redshift Lyman-$\alpha$ Forest. We make use of the correlation between the Lyman-$\alpha$ optical depth and the…

Astrophysics · Physics 2009-10-31 Enrique Gaztanaga , Rupert A. C. Croft

We present predictions of Ly-alpha forest-galaxy correlations at z=3 from Eulerian simulations that include the effects of galactic winds, driven primarily by supernova explosions. Galactic winds produce expanding bubbles of shock-heated…

Astrophysics · Physics 2009-11-10 Juna A. Kollmeier , Jordi Miralda-Escude , Renyue Cen , Jeremiah P. Ostriker

Techniques for the statistical analysis of the \Lya\ forest in high redshift quasars are developed, and applied to the low resolution (25 \AA) spectra of 29 of the 33 quasars in the Schneider-Schmidt-Gunn (SSG) sample.We find that the mean…

Astrophysics · Physics 2009-10-22 William H. Press , George B. Rybicki , Donald P. Schneider

Models for structure formation attempt to predict the power spectrum of density perturbations in the present universe from the initial power spectrum and the nature of dark matter. Observational constraints on the power spectrum at…

Astrophysics · Physics 2007-05-23 K. Subramanian , T. Padmanabhan
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