Related papers: Ionisation Structure in Accretion Shocks with a Co…
[Fe II] emission lines are prominent in the infrared (IR), and they are important diagnostic tools for radiative atomic shocks. We investigate the emission characteristics of [Fe II] lines using a shock code developed by Raymond (1979) with…
In this work we studied the two-dimensional ionization structure of the circumnuclear and extranuclear regions in a sample of six low-z Ultraluminous Infrared Galaxies using Integral Field Spectroscopy. The ionization conditions in the…
It is believed that protostellar accretion disks to be formed from nearly ballistic infall of the molecular matters in rotating core collapse. Collisions of these infalling matters lead to formation of strong supersonic shocks, which if…
Direct-imaging surveys have looked for accreting planets through their accretion tracers such as H alpha but have been less fruitful than expected. However, up to now, hydrogen-line emission at accreting planets has been estimated primarily…
We present an analysis of the X-ray spectra of two strongly magnetic cataclysmic variables, DP Leo and WW Hor, made using XMM-Newton. Both systems were in intermediate levels of accretion. Hard optically thin X-ray emission from the shocked…
The key aspect determining the post-formation luminosity of gas giants has long been considered to be the energetics of the accretion shock at the planetary surface. We use 1D radiation-hydrodynamical simulations to study the radiative loss…
We have chosen a reduced set of 18 ionization rate equations (for ions of H, C, N, O, S and Ne), which allow us to obtain a moderately accurate estimate of the non-equilibrium radiative cooling function. We evaluate the accuracy of this…
Far-infrared spectroscopy reveals gas cooling and its underlying heating due to physical processes taking place in the surroundings of protostars. These processes are reflected in both the chemistry and excitation of abundant molecular…
(abbreviated version of the abstract) We study the physics of cyclotron line formation in the high-energy spectra of accreting X-ray pulsars using Monte Carlo methods, assuming that the line-forming region is a low-density electron plasma…
Hydrogen recombination lines (HRLs) are valuable diagnostics of the physical conditions in ionized regions around high-mass stars. Understanding their broadening mechanisms and intensity trends can provide insights into the densities,…
The crystallographic structure of iron under extreme conditions is a key benchmark for cutting-edge experimental and numerical methods. Moreover, it plays a crucial role in understanding planetary cores, as it significantly influences the…
We solve the equations of radiation hydrodynamics in the two-temperature fluid approximation on an adaptive grid. The temperature structure depends upon the electron-ion energy exchange length, $l_{ei}$, and the electron conduction length,…
In the work described here we investigate atomic processes leading to the formation of emission lines within the IRIS wavelength range at temperatures near $10^5$~K. We focus on (1) non-equilibrium and (2) density-dependent effects…
We calculate the ionization fraction of protostellar alpha disks, taking into account vertical temperature structure, and the possible presence of trace metal atoms. Both thermal and X-ray ionization are considered. Previous investigations…
If an accretion disk around a black hole is illuminated by hard X-rays from non-thermal coronae, fluorescent iron lines will be emitted from the inner region of the accretion disk. The emission line profiles will show a variety of strong…
A planetary growth rate, a.k.a., the mass accretion rate, is a fundamental parameter in planet formation, as it determines a planet's final mass. Planetary mass accretion rates have been estimated using hydrogen lines, based on the models…
We analyze spectroscopic and photometric observations of the eclipsing polar BS Tri. The polar's light curve shape variations can be interpreted by changing contributions of the accretion stream to the integral radiation of the system.…
(Abridged) In the low-mass star formation process, theoretical models predict that material from the infalling envelope could be shocked as it encounters the outer regions of the disk. Nevertheless, only a few protostars show evidence of…
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 present a full set of model atmosphere equations for the accretion disk around a supermassive black hole irradiated by hard X-ray lamp of power-law spectral distribution. Model equations allow for multiple Compton scattering of radiation…