Related papers: Imaging HII Regions from Galaxies and Quasars Duri…
The SKA is a unique instrument to open a window on many aspects of galaxy formation and evolution which can be examined in our Local Universe. Here I will focus on the outermost regions of galaxies which can be observed with sufficient…
The future new-generation radio telescope SKA (Square Kilometre Array) and its precursors will provide a rapidly growing number of polarized radio sources. Hundred and thousands polarized background sources can be measured towards nearby…
Density inhomogeneity in the intergalactic medium (IGM) can boost the recombination rate of ionized gas substantially, affecting the growth of HII regions during reionization. Previous attempts to quantify this effect typically failed to…
Ultraviolet (UV) and X-ray photons from active galactic nuclei (AGNs) can ionize hydrogen in the intergalactic medium (IGM). We solve radiative transfer around AGNs in high redshift to evaluate the 21-cm line emission from the neutral…
Observations of the epoch of reionization give us clues about the nature and evolution of the sources of ionizing photons, or early stars and galaxies. We present a new suite of structure formation and radiative transfer simulations from…
Two major questions in galaxy evolution are how star-formation on small scales leads to global scaling laws and how galaxies acquire sufficient gas to sustain their star formation rates. HI observations with high angular resolution and with…
By depleting the ionizing photon budget available to expand cosmic HII regions, recombining systems (or Lyman limit systems) can have a large impact during (and following) cosmic reionization. Unfortunately, directly resolving such…
We study the formation and evolution of HII regions around the first stars formed at z=10-30. We use a one-dimensional Lagrangian hydrodynamics code which self-consistently incorporates radiative transfer and non-equilibrium primordial gas…
Absorption or emission against the cosmic microwave background radiation (CMB) may be observed in the redshifted 21cm line if the spin temperature of the neutral intergalactic medium prior to reionization differs from the CMB temperature.…
Searches for Lyman-alpha emission lines are among the most effective ways to identify high-redshift galaxies. They are particularly interesting because they probe not only the galaxies themselves but also the ionization state of the…
The epoch of reionization (EoR) sets a fundamental benchmark in cosmic structure formation, corresponding to the formation of the first luminous objects that act to ionize the neutral intergalactic medium (IGM). Recent observations at…
21 cm intensity mapping (IM) has the potential to be a strong and unique probe of cosmology from redshift of order unity to redshift potentially as high as 30. For post-reionization 21 cm observations, the signal is modulated by the thermal…
Only in recent years has the realization emerged that galaxies do not dominate the universal baryon budget but are merely the brightest pearls of an underlying Cosmic Web. Although the gas in these inter-galactic filaments is moderately to…
One of the key science drivers for the development of the SKA is to observe the neutral hydrogen, HI, in galaxies as a means to probe galaxy evolution across a range of environments over cosmic time. Over the past decade, much progress has…
Reionization is thought to be dominated by low mass galaxies, while direct observations of resolved galaxies probe only the most massive, rarest objects. The cross-correlation between fluctuations in the surface brightness of the cumulative…
A number of very small isolated HII regions have been discovered at projected distances up to 30 kpc from their nearest galaxy. These HII regions appear as tiny emission line objects in narrow band images obtained by the NOAO Survey for…
The observed power spectrum of redshifted 21cm fluctuations is known to be sensitive to the astrophysical properties of the galaxies that drove reionization. Thus, detailed measurements of the 21cm power spectrum and its evolution could…
It is possible that the properties of HII regions during reionization depend sensitively on many poorly constrained quantities (the nature of the ionizing sources, the clumpiness of the gas in the IGM, the degree to which photo-ionizing…
The Square Kilometre Array (SKA) will be a formidable instrument for the detailed study of neutral hydrogen (HI) in external galaxies and in our own Galaxy and Local Group. The sensitivity of the SKA, its wide receiver bands, and the…
Lyman-alpha forest absorption spectra towards quasars at z ~ 6 show regions of enhanced transmission close to their source. Several authors have argued that the apparently small sizes of these regions indicate that quasar ionization fronts…