相关论文: Cosmic Reionization on Computers: The Evolution of…
We present a new hybrid code for large volume, high resolution simulations of cosmic reionization, which utilizes a N-body algorithm for dark matter, physically motivated prescriptions for baryons and star formation, and an adaptive ray…
The reionization process is expected to be prolonged by the small-scale absorbers (SSAs) of ionizing photons, which have been seen as Lyman-limit systems in quasar absorption line observations. We use a set of semi-numerical simulations to…
We explore the connection between the stellar component of galaxies and their host halos during the epoch of reionization ($5 \leq z\leq10$) using the CROC (Cosmic Reionization on Computers) simulations. We compare simulated galaxies with…
The timeline of cosmic reionization remains uncertain despite sustained efforts to study how the ionizing output of early galaxies shaped the intergalactic medium (IGM). Using the semi-numerical code LIMFAST, we investigate the prospects…
During reionization, intergalactic ionization fronts (I-fronts) are sources of Ly$\alpha$ line radiation produced by collisional excitation of hydrogen atoms within the fronts. In principle, detecting this emission could provide direct…
The latest measurements of CMB electron scattering optical depth reported by Planck significantly reduces the allowed space of HI reionization models, pointing toward a later ending and/or less extended phase transition than previously…
We show the universe was reionized twice, first at z~15-16 and second at z~6. Such an outcome appears inevitable, when normalizing to two well determined observational measurements, namely, the epoch of the final cosmological reionization…
We present a quantitative model of Lyman-alpha (Ly-alpha) emission throughout cosmic history and determine the prospects for intensity mapping of spatial fluctuations in the Ly-alpha signal. Since i) our model assumes at z>6 the minimum…
Reionization of the cosmic neutral hydrogen by the first stars in the Universe is an inhomogeneous process which produces spatial fluctuations in free electron density. These fluctuations lead to observable signatures in cosmological probes…
We present new measurements of the intensity of the ionizing ultraviolet background and the global emissivity of ionizing photons over 2 < z < 5. Our results are based on a suite of updated measurements of physical properties of the…
We present a computationally efficient and fast semi-numerical technique for simulating the Lyman-$\alpha$ (Ly$\alpha$) absorption optical depth in presence of neutral hydrogen "islands" left over from reionization at redshifts $5 \lesssim…
Lyman-Break Galaxy (LBG) samples observed during reionization ($z\gtrsim6$) with Hubble Space Telescope's Wide Field Camera 3 are reaching sizes sufficient to characterize their clustering properties. Using a combined catalog from the…
We used cosmological simulation with self-consistent radiative transfer to investigate the physical nature of Lyman Limit systems at z=4. In agreement with previous studies, we find that most of Lyman Limit systems are ionized by the…
We study the signal in the Cosmic Microwave Background (CMB) polarization anisotropy resulting from patchy reionization. It is well known that the primordial polarization of the CMB is very sensitive to the details of reionization.…
The epoch of reionization (6 < z < 10) marks the period in our universe when the first large galaxies grew to fruition, and began to affect the universe around them. Massive stars, and potentially accreting supermassive black holes, filled…
Observations of high-redshift Ly-alpha sources are a major tool for studying the high-redshift Universe. We discuss the effect of the reionizing intergalactic medium on the observability of Ly-alpha sources based on large simulations of…
One of the major challenges in observational cosmology is related to the redshift evolution of the average hydrogen ionization in the Universe. In order to probe the ionization level of the IGM and the ionization capabilities of bright QSOs…
While emission and absorption lines of the 21 cm spin-flip transition of neutral Hydrogen are intrinsically unpolarized, a magnetic field creates left- and right-handed polarized components through the Zeeman effect. Here we consider the…
Recently, the Lyman-$\alpha$ (Ly$\alpha$) forest flux auto-correlation function has been shown to be sensitive to the mean free path of hydrogen-ionizing photons, $\lambda_{\text{mfp}}$, for simulations at $z \geq 5.4$. Measuring…
I show that advanced simulations of cosmological reionization are able to fit the observed data on the mean transmitted flux in the hydrogen Lyman-alpha line at z~6. At the same time, posteriori models can be constructed that also produce a…