Related papers: Quasar Ionization Front Ly{\alpha} Emission in an …
Recent theoretical work has suggested that Lyman-alpha nebulae could be substantially polarized in the Lyman-alpha emission line, depending on the geometry, kinematics, and powering mechanism at work. Polarization observations can therefore…
The sources which reionized the Intergalactic Medium by redshift ~6 are still unknown. A severe constraint on the ionization process is the low emissivity required to maintain the ionization in the Lyman-{\alpha} forest.…
We present a Bayesian inference on the neutral hydrogen fraction of the intergalactic medium (IGM), $x_{\textrm{HI}}$, at $z \sim$ 6-8 using the properties of Lyman break galaxies during the Epoch of Reionization. We use large samples of…
The intense UV radiation from a highly luminous QSO should excite fluorescent Ly-alpha emission from any nearby neutral hydrogen clouds. We present a very deep narrow-band search for such emission near the z=2.168 quasar PKS 0424-131,…
Recent observations of high redshift quasar spectra reveal long gaps with little flux. A small or no detectable flux does not by itself imply the intergalactic medium (IGM) is neutral. Inferring the average neutral fraction from the…
We report new measurements of the intergalactic medium (IGM) Ly$\alpha$ and Ly$\beta$ effective optical depth at $5.3<z<6.5$, using a new sample of quasar sightlines including 32 quasars at $6.308\le z\le7.00$. These quasars provide a large…
As Lyman-alpha photons are scattered by neutral hydrogen, a change with redshift in the Lyman-alpha equivalent width distribution of distant galaxies offers a promising probe of the degree of ionization in the intergalactic medium and hence…
The intense radiation emitted by luminous quasars dramatically alters the ionization state of their surrounding IGM. This so-called proximity effect extends out to tens of Mpc, and manifests as large coherent regions of enhanced…
Lyman-alpha photons from the first radiating sources in the Universe play a pivotal role in 21-cm radio detections of Cosmic Dawn and the Epoch of Reionization. Comments are provided on the effect of the hyperfine structure of hydrogen on…
We explore how the assumption of ionization equilibrium modulates the modeled intergalactic medium (IGM) at the end of the hydrogen Epoch of Reionization using the cosmological radiation hydrodynamic \textsc{Technicolor Dawn} simulation. In…
We present a study of a double-peaked Ly$\alpha$ emitter, named LAE-11, found in the proximity zone of QSO J0910-0414 at $z\sim6.6$. We use a combination of deep photometric data from Subaru Telescope, HST, and JWST with spectroscopic data…
This is the second paper in a series whose aim is to predict the power spectrum of intensity and polarized intensity from cosmic reionization fronts. After building the analytic models for intensity and polarized intensity calculations in…
Recently, models of the quasar luminosity function (QLF) rooted on large observational compilations have been produced that, unlike their predecessors, feature a smooth evolution with time. This bypasses the need to assume an ionizing…
Observations of the intergalactic medium (IGM) suggest that quasars reionize HeII in the IGM at z ~ 3. We have run a set of 190 and 430 comoving Mpc simulations of HeII being reionized by quasars to develop an understanding of the nature of…
Measurement of the red damping wing of neutral hydrogen in quasar spectra provides a probe of the epoch of reionization in the early Universe. Such quantification requires precise and unbiased estimates of the intrinsic continua near…
Ly$\alpha$ photons scattered by neutral hydrogen atoms in the circumgalactic media or produced in the halos of star-forming galaxies are expected to lead to extended Ly$\alpha$ emission around galaxies. Such low surface brightness…
We use numerical simulations of hydrogen reionization by stellar sources in the context of LCDM cosmogonies to investigate the 21 (1+z) cm radio signal expected from the diffuse intergalactic medium (IGM) prior to the epoch of reionization…
The resonantly scattered Lyman-$\alpha$ line illuminates the extended halos of neutral hydrogen in the circumgalactic medium of galaxies. We present integral field Keck Cosmic Web Imager observations of double-peaked, spatially extended…
We present measurements of the intergalactic medium (IGM) temperature within ~5 proper Mpc of seven luminous quasars at z~6. The constraints are obtained from the Doppler widths of Lyman-alpha absorption lines in the quasar near-zones and…
Lyman $\alpha$ (Ly$\alpha$) emission is one of few observable features of galaxies that can trace the neutral hydrogen content in the Universe during the Epoch of Reionization (EoR). To accomplish this we need an efficient way to survey for…