Related papers: Redshift Evolution of the Low-Column Density Lyman…
We have measured the distribution function of the flux decrement caused by Lyman alpha forest absorption in a new sample of high resolution QSO spectra. The observations are compared to the results from two simulations of the Lya forest: an…
[Abridged] We present a physical model for the evolution of the ultraviolet (UV) luminosity function (LF) of high-z galaxies taking into account in a self-consistent way their chemical evolution and the associated evolution of dust…
The evolution of the expansion rate of the Universe results in a drift in the redshift of distant sources over time. A measurement of this drift would provide us with a direct probe of expansion history. The Lyman alpha forest has been…
We investigate the effects of AGN heating and the ultraviolet background on the low-redshift Lyman-$\alpha$ forest column density distribution (CDD) using the Illustris simulation. We show that Illustris reproduces observations at $z =0.1$…
We propose that a large fraction of the QSO Lyman limit absorption systems (LLS) observed at high redshift (z > 3) originate from gas trapped in small objects, such as minihalos, that form prior to reionization. In the absence of a strong…
The amplitude of fluctuations in the Ly-a forest on small spatial scales is sensitive to the temperature of the IGM and its spatial fluctuations. The temperature of the IGM and its spatial variations contain important information about…
The Lyman-$\alpha$ forests observed in the spectra of high-redshift quasars can be used as a tracer of the cosmological matter density to study baryon acoustic oscillations (BAO) and the Alcock-Paczynski effect. Extraction of cosmological…
We present a detailed analysis of a high resolution spectrum of the damped Ly$\alpha$ system at $z_{\rm abs}$~=~2.8112toward PKS~0528-250. The absorption redshift is slightly larger than the emission redshift of the quasar. We estimate the…
We compare the improved measurement of the Lya forest flux probability distribution at 1.7<z<3.2 presented by Kim et al. (2007) to a large set of hydrodynamical simulations of the Lya forest with different cosmological parameters and…
We develop a prescription for characterizing the strengths of metal lines associated with Lyman-alpha forest absorbers (LYFAs) of a given neutral hydrogen column density N_HI and metallicity [Fe/H]. This Line Observability Index (LOX) is…
We present high S/N echelle spectra of the recently discovered ultraluminous QSO APM 08279+5255 and use these data to re-examine the abundance of Carbon in Ly alpha forest clouds. In agreement with previous work, we find that approximately…
We present an estimate of the cosmological evolution of the field galaxy luminosity function (LF) in the rest frame 4400 Angstrom B -band up to redshift z=3.5. To this purpose, we use a composite sample of 1541 I--selected galaxies selected…
We present a detailed analysis of 99 optically thin C III absorption systems at redshift, $0.2 \le z \le 0.9$ associated with neutral hydrogen column densities in the range, $15 \le {\rm log}$ $N_{\rm H\,I}$ ($cm^{-2}$) $\le 16.2$. Using…
Recent observations of the Lyman-break galaxy (LBG) luminosity function (LF) from z~6-10 show a steep decline in abundance with increasing redshift. However, the LF is a convolution of the mass function of dark matter halos (HMF)--which…
Using the redshift evolution of the neutral hydrogen density, as inferred from observations of damped Ly$\alpha$ clouds, we calculate the evolution of star formation rates and elemental abundances in the universe. For most observables our…
We analyze evolution of the basic properties of simulated large scale structure elements formed by dark matter (DM LSS) and confront it with the observed evolution of the Lyman-$\alpha$ forest. In three high resolution simulations we…
The average flux decrement shortward the Ly$_{\alpha}$ emission, due to the well-known ``forest'' of absorptions, has been measured in the spectra of 8 quasars. Quasi-simultaneous optical and IUE observations of the two low redshift quasars…
Recent observations of the Lyman-alpha forest show large-scale spatial variations in the intergalactic Lyman-alpha opacity that grow rapidly with redshift at z>5, far in excess of expectations from empirically motivated models. Previous…
In this work, I investigate the properties of Lyman limit systems (LLSs) using state-of-the-art zoom-in cosmological galaxy formation simulations with on the fly radiative transfer, which includes both the cosmic UV background (UVB) and…
Ly$\alpha$ forests are usually associated with intergalactic gas clouds intercepting the quasar sight--line. Using as an example the Ly$\alpha$ forest of QSO 0055--26 ($z_{em} = 3.66$), we show that the probability of observing a line at…