Related papers: Lyman-alpha emission as a tool to study high redsh…
The 21-cm and Lyman Alpha lines are the dominant line-emission spectral features at opposite ends of the spectrum of hydrogen. Each line can be used to create three dimensional intensity maps of large scale structure. The sky brightness at…
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…
We have completed spectroscopic observations using LRIS on the Keck 1 telescope of 30 very high redshift quasars, 11 selected for the presence of damped Ly-alpha absorption systems and 19 with redshifts z > 3.5 not previously surveyed for…
We present a semi-analytical model of star formation which explains simultaneously the observed UV luminosity function of high redshift Lyman break galaxies (LBGs) and luminosity functions of Lyman-alpha emitters. We consider both models…
Mapping the intergalactic medium (IGM) in Lyman-$\alpha$ emission would yield unprecedented tomographic information on the large-scale distribution of baryons and potentially provide new constraints on the UV background and various feedback…
We present a formalism that incorporates hydrogen Lyman-alpha (Ly$\alpha$) polarization arising from the scattering of radiation in galaxy halos into the intensity mapping approach. Using the halo model, and emission profiles based on…
Damped Ly\alpha\ systems (DLAs) observed in the quasar spectra are characterized by a high neutral hydrogen column density $N_{HI}>2\times 10^{20}{\rm\ cm^{-2}}$. The absorption wing profiles are often fitted using the Voigt function due to…
A scenario is explored in which Lyman alpha absorbers at low redshift arise from lines of sight through extended galaxy disks, including those of dwarf and low surface brightness galaxies. A population of galaxies is simulated based upon…
A variety of independent observational studies have now reported a significant decline in the fraction of Lyman-break galaxies which exhibit Ly-a emission over the redshift interval z=6-7. In combination with the strong damping wing…
We have used the Green Bank Telescope (GBT) and Berkeley-Illinois-Maryland Association (BIMA) array to search for redshifted millimetre absorption in a sample of damped Lyman-alpha absorption systems (DLAs). This brings the number of…
The escape of Lyman-alpha photons at redshifts greater than two is an ongoing subject of study and an important quantity to further understanding of Lyman-alpha emitters (LAEs), the transmission of Lyman-alpha photons through the…
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 present an analysis of HI Lyman-alpha emission in deep VLT/MUSE observations of two highly magnified and extended galaxies at z=3.5 and 4.03, including a newly discovered, almost complete Einstein ring. While these Lyman-alpha haloes are…
In this work we model the observed evolution in comoving number density of Lyman-alpha blobs (LABs) as a function of redshift, and try to find which mechanism of emission is dominant in LAB. Our model calculates LAB emission both from…
We present predictions for the abundance of Ly-$\alpha$ emitters in hierarchical structure formation models. We use the {\tt GALFORM} semi-analytical model to explore the impact on the predicted counts of varying assumptions about the…
We use hydrodynamic cosmological simulations to study damped Lyman-alpha (DLA) and Lyman limit (LL) absorption at redshifts z=2-4 in five variants of the cold dark matter scenario. Our standard simulations resolve the formation of dense…
Extended Lyman-alpha emission is now commonly detected around high redshift galaxies through stacking and even on individual basis. Despite recent observational advances, the physical origin of these Lyman-alpha halos (LAHs), as well as…
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…
Molecular hydrogen is quite underabundant in damped Lyman-alpha systems at high redshift, when compared to the interstellar medium near the Sun. This has been interpreted as implying that the gas in damped Lyman-alpha systems is warm. like…
During recombination, the cosmic background radiation is disturbed, in particular, by Lyman-alpha emissions from neutral hydrogen. It is proposed to account for the subsequent time-dependent partial thermalization of the Lyman-alpha energy…