Related papers: Revisiting He-like X-ray Emission Line Plasma Diag…
We present a systematic measurement of the X-ray emission asymmetries in the K-shell dielectronic, trielectronic, and quadruelectronic recombination of free electrons into highly charged ions. Iron ions in He-like through O-like charge…
Using a geometry consisting of a hot central Comptonizing plasma surrounded by a thin accretion disk, we model the optical through hard X-ray spectral energy distributions of the type 1 Seyfert galaxies NGC 3516 and NGC 7469. As in the…
We examine the impact of helium reionization on the structure of the intergalactic medium (IGM). We model the reionization using a radiative transfer (RT) code coupled to the combined gravity hydrodynamics code Enzo. Neutral hydrogen and…
Chemistry in diffuse molecular clouds relies primarily on rapid ion-molecule reactions. Formation of the initial ions, H$^+$ and H$_2^+$, is dominated by cosmic-ray ionization of H and H$_2$, making the cosmic-ray ionization rate (denoted…
A proper modelling of the cosmic-ray ionisation rate within gas clouds is crucial to describe their chemical evolution accurately. However, this modelling is computationally demanding because it requires the propagation of cosmic rays…
Standard measures of opacity, the imaginary part of the atomic scattering factor $f_2$ and the x-ray mass attenuation coefficient $\mu/\rho$, are evaluated in shock-heated boron, boron carbide and boron nitride plasmas. The Hugoniot…
The linear stability analysis of an optically thin plasma where a general reaction proceeds, including chemical relaxation time effects, is carried out . A fifth order dispersion equation (instead of the fourth order one resulting when such…
The effects of radiation on the structure of shocks in a fully-ionized plasma are investigated by solving the steady-state fluid equations for ions, electrons, and radiation. The electrons and ions are assumed to have the same bulk velocity…
We describe a method to compute photon-matter interaction and atomic dynamics with X-ray lasers using a hybrid code based on classical molecular dynamics and collisional-radiative calculations. The forces between the atoms are dynamically…
We measure several properties of the reionization process and the corresponding low-frequency 21-cm signal associated with the neutral hydrogen distribution, using a large volume, high resolution simulation of cosmic reionization. The…
We assess the possibility to detect the warm-hot intergalactic medium (WHIM) in emission and to characterize its physical conditions and spatial distribution through spatially resolved X-ray spectroscopy, in the framework of the recently…
Line intensity mapping (LIM) is rapidly emerging as a powerful technique to study galaxy formation and cosmology in the high-redshift Universe. We present LIM estimates of select spectral lines originating from the interstellar medium (ISM)…
We discuss the effects of collisional enhancement of Balmer lines on the determination of the primordial helium abundance. To this aim, we present a photoionization model of the metal-poor extragalactic HII region SBS 0335--052. We show…
Emission lines from highly-excited states (n >= 5) of H- and He-like ions have been detected in astrophysical sources and fusion plasmas. For such excited states, R-matrix or distorted wave calculations for electron-impact excitation are…
The current status of various thermal and statistical descriptions of particle production in the ultra-relativistic heavy-ion collisions experiments is presented in detail. We discuss the formulation of various types of thermal models of a…
High ionisation lines in the soft X-ray band are generally associated to either interstellar hot gas along the line of sight or to photoionised gas intrinsic to the source. In the low-mass X-ray binary 4U 1820-30, the nature of these lines…
In this paper we have studied the chemistry of C, H, N, O, and S compounds corresponding to ions of masses <=40 amu in the inner coma of the comet 1P/Halley. The production rates, loss rates, and ion mass densities are calculated using the…
Effects of radio-frequency power and driven frequency on the two-dimensional (axial and radial) distributions of electron density and temperature were experimentally investigated in low pressure capacitively coupled argon plasmas. The…
Accurate determination of total oxidant concentration [Ox]tot in nonthermal plasma treated aqueous systems remains a critical challenge due to the transient nature of reactive oxygen and nitrogen species and the subjectivity of conventional…
The reionization of the second electron of helium shapes the physical state of intergalactic gas at redshifts between 2 < z < 5. Because performing full in situ radiative transfer in hydrodynamic simulations is computationally expensive for…