Related papers: Physics of Cosmic Reionization
One of the most sought-after signatures of reionization is a rapid increase in the ionizing background (usually measured through the Lyman-alpha optical depth toward distant quasars). Conventional wisdom associates this with the "overlap"…
(Abridged) Cosmology faces three distinct challenges in the next decade. (1) The dark sector, both dark matter and dark energy, dominates the Universe. Key questions include determining the nature of both. Improved observational probes are…
Probing the growth of structure from the epoch of hydrogen recombination to the formation of the first stars and galaxies is one of the most important uncharted areas of observational cosmology. Far-IR spectroscopy covering $\lambda$…
The epoch of reionization is a milestone of cosmological structure formation, marking the birth of the first objects massive enough to yield large numbers of ionizing photons. The mechanism and timescale of reionization remain largely…
Cosmic Microwave Background temperature and polarization anisotropies from Planck have estimated a lower value of the optical depth to reionization ($\tau$) compared to WMAP. A significant period in the reionization history would then fall…
We use a compilation of cosmic microwave anisotropy data to constrain the epoch of reionization in the Universe, as a function of cosmological parameters. We consider spatially-flat cosmologies, varying the matter density $\Omega_0$ (the…
X-ray polarimetry is now providing a new way to look at the high energy sky. The addition of two observables, polarization fraction and angle, reveals crucial new information on the structure of accretion flows and magnetic fields in…
Understanding the formation and evolution of the first stars and galaxies represents one of the most exciting frontiers in astronomy. Since the universe was filled with hydrogen atoms at early times, the most promising probe of the epoch of…
The history of the transition from a neutral intergalactic medium to one that is almost fully ionized can reveal the character of cosmological ionizing sources. In this talk I will discuss the implications for rival reionization scenarios…
We use numerical simulations of cosmic reionization and radiative processes related to the HI 21 cm emission line to produce synthetic radio maps as seen by next generation radio telescopes that will operate at low radio frequencies (e.g.…
Magnetic fields are ubiquitous in the Universe. They seem to be present at virtually all scales and all epochs. Yet, whether the fields on cosmological scales are of astrophysical or cosmological origin remains an open major problem. Here…
The redshifted 21-cm line of distant neutral H atoms provides a probe of the cosmic ``dark ages'' and the epoch of reionization (``EOR'') which ended them. The radio continuum produced by this redshifted line can be seen in absorption or…
We investigate how the nature of the galaxies that reionized the Universe affects the duration of reionization. We contrast two sets of models: one in which galaxies on the faint side of the luminosity function dominate the ionizing…
An ionization plays a key role in formation of stars, planets and their atmospheres. Cosmic rays (CR) are the main source of the ionization, therefore it is important to know and be able to estimate fluxes of galactic and stellar cosmic…
The polarization of the Cosmic Microwave Background (CMB) radiation carries essential information on early stages of the Universe such as the cosmic inflation, forming cosmological structures through gravitational lensing, and the epoch of…
A brief summary of some highlights in the study of high energy astrophysical sources over the past decade is presented. It is argued that the great progress that has been made derives largely from the application of new technology to…
I discuss and illustrate the development of large-scale structure in the Universe, emphasising in particular the physical processes and cosmological parameters that most influence the observationally accessible aspects of structure at large…
Cosmic ray story begins at the beginning of XX century. More then 100 years later, most of the main issues are still open questions, as sources, acceleration mechanism, propagation and composition. There is a continuing fascination with the…
The idea of possible time or space variations of the `fundamental' constants of nature, although not new, is only now beginning to be actively considered by large numbers of researchers in the particle physics, cosmology and astrophysics…
The history of reionization reflects the cumulative injection of ionizing photons by sources and the absorption of ionizing photons by sinks. The latter process is traditionally described in terms of a "clumping factor" which encodes the…