Related papers: Photoionization and Opacity
We develop a model for predicting fine- and hyperfine intensities in the direct photoionization of molecules based on the separability of electron and nuclear spin states from vibrational-electronic states. Using spherical tensor algebra,…
Extensive resonance structures are manifest in R-Matrix (RM) calculations. However, there exist a large number of highly excited electronic configurations that may contribute to background non-resonant bound-free opacity in high-temperature…
We consider photo ionization of an atom which, due to passing through a diffraction grating, is prepared in a multi-site state possessing a periodic space structure with alternating maxima and minima. It has been found that this process…
The Magellanic Stream and several high velocity clouds have now been detected in optical line emission. The observed emission measures and kinematics are most plausibly explained by photoionization due to hot, young stars in the Galactic…
In this study, we have investigated the photoionization cross section of an on-center hydrogenic impurity in a multi-layered spherical quantum dot. The electronic energy levels and their wave functions have been determined fully numerically…
We introduce and test a new and highly efficient method for treating the thermal and radiative effects influencing the energy equation in SPH simulations of star formation. The method uses the density, temperature and gravitational…
Interfacial roughness is prevalent in 1D photonic crystals and other layered structures, but is not generally accounted for in their design nor the analysis of their optical properties due to a lack of simple theoretical approaches. We…
Opacity is an important ingredient of the evolution of stars. The calculation of opacity coefficients is complicated by the fact that the plasma contains partially ionized heavy ions that contribute to opacity dominated by H and He. Up to…
To elucidate the permeation of cosmic ultraviolet (UV) background radiation into a pregalactic cloud and subsequent ionization, the frequency-dependent radiative transfer equation is solved, coupled with the ionization process. A spherical…
A methodology is developed to compute photoionization cross-sections beyond the electric dipole (BED) approximation from response theory, using Gaussian type orbitals and plane waves for the initial and final states, respectively. The…
Photoionization of a cold atomic sample offers intriguing possibilities to observe collective effects at extremely low temperatures. Irradiation of a rubidium condensate and of cold rubidium atoms within a magneto-optical trap with laser…
We present an extension of TRAPHIC, the method for radiative transfer of ionising radiation in smoothed particle hydrodynamics simulations that we introduced in Pawlik & Schaye (2008). The new version keeps all advantages of the original…
Laboratory (laser and Z-pinch) opacity measurements of well-characterized plasmas provide data to assist inertial confinement fusion, astrophysics and atomic-physics research. In order to test the atomic-physics codes devoted to the…
The equation of state and radiative opacities of partially ionized, strongly magnetized hydrogen plasmas, presented in a previous paper [ApJ 585, 955 (2003), astro-ph/0212062] for the magnetic field strengths 8.e11 G < B < 3.e13 G, are…
Photoionization of an atom $A$ by a strong laser field in the presence of a spatially well-separated neighboring atom $B$ is considered. The laser field frequency is assumed to lie below the ionization potential of atom $A$ and be resonant…
We investigate the multi-photon process of above-threshold ionization for the light elements hydrogen, carbon, nitrogen and oxygen in the hard x-ray regime. Numerical challenges are discussed and by comparing Hartree-Fock-Slater…
For photoionized plasmas, electron energy-loss rates due to radiative recombination (RR) are required for thermal equilib- rium calculations, which assume a local balance between the energy gain and loss. While many calculations of total…
Two-photon ionization of an alkali-metal atom in the presence of a uniform electric field is investigated using a standardized form of local frame transformation and generalized quantum defect theory. The relevant long-range quantum defect…
Modifications of photoionization arising from resonant electron-electron correlations between neighbouring atoms in an atomic sample are studied. The sample contains atomic species A and B, with the ionization potential of A being smaller…
We use the photon flux and absorption tracer algorithm presented in Katz et al.~2018, to characterise the contribution of haloes of different mass and stars of different age and metallicity to the reionization of the Universe. We employ a…