Related papers: Exact solutions for the populations of the n-level…
We present a new methodology for the analysis of the emission lines of the interstellar medium in the Narrow Line Regions around type-2 Active Galactic Nuclei. Our aim is to provide a recipe that can be used for large samples of objects in…
Recent observations reveal that the central star of the planetary nebula Abell 48 exhibits spectral features similar to massive nitrogen-sequence Wolf-Rayet stars. This raises a pertinent question, whether it is still a planetary nebula or…
We present a new approach to study planetary nebulae using integral field spectroscopy. VLT@VIMOS datacube of the planetary nebula Abell 14 is analysed in three different ways by extracting: (i) the integrated spectrum, (ii) 1-dimensional…
We present a detailed comparison of optical H II region spectra to photoionization models based on modern stellar atmosphere models. We examine both spatially resolved and integrated emission-line spectra of the HII regions DEM L323, DEM…
We present analytical solutions to the steady state injection-condensation-coagulation equation of aerosols in the atmosphere. These solutions are appropriate under different limits but more general than previously derived analytical…
We explore a new fashion, named energy-resolved population image (EPI), to represent on an equal footing the temporary electronic transition and nuclear motion during laser-molecular interaction. By using the EPI we have intuitively…
A mayor problem that arises in the computation of stellar atmosphere models is the self consistent determination of the temperature distribution via the constraint of energy conservation. The energy balance includes the gains due to the…
Emission lines in ionized nebulae can provide strong and useful constraints on the properties of both ionizing and non-ionizing stellar populations in regions with star formation, provided that stellar evolution and stellar atmosphere…
For the calculation of complex neutral/ionized gas phase chemical equilibria, we present a semi-analytical versatile and efficient computer program, called FastChem. The applied method is based on the solution of a system of coupled…
We present results on the properties of neon emission in $z\sim2$ star-forming galaxies drawn from the MOSFIRE Deep Evolution Field (MOSDEF) survey. Doubly-ionized neon ([NeIII]3869) is detected at $\geq3\sigma$ in 61 galaxies, representing…
Calorimetric and coalescence techniques have been employed to probe equilibration for hot nuclei produced in heavy ion collisions of 35 to 55 MeV/u projectiles with medium mass targets. Entrance channel mass asymmetries and energies were…
Context. Level population inversion of hydrogen atoms in ionized gas may lead to stimulated emission of hydrogen recombination lines, and the level populations can in turn be affected by powerful stimulated emissions. Aims. In this work the…
Identifying the nucleosynthesis processes behind heavy-element enrichment in stellar atmospheres is challenging. It typically relies on comparing observed abundance-to-iron ratios with theoretical predictions relative to the Sun, but this…
The primary X-ray diagnostic lines in He-like ions are mainly excited by electron impact from the ground level to the n = 2 levels, but at high temperatures n > 2 levels are also excited. In order to describe the atomic processes more…
Deep spectroscopy of the planetary nebula (PN) NGC\,6153 shows that its heavy element abundances derived from optical recombination lines (ORLs) are ten times higher than those derived from collisionally excited lines (CELs), and points to…
Three non-equilibrium photoionisation algorithms for hydrodynamical grid-based simulation codes are compared in terms of accuracy, timestepping criteria, and parallel scaling. Explicit methods with first-order time accuracy for photon…
Spectral lines from N-like ions can be used to measure the temperature and density of various types of astrophysical plasmas. The atomic databases of astrophysical plasma modelling codes still have room for improvement in their…
The AC power flow equations describe the steady-state behavior of the power grid. While many algorithms have been developed to compute solutions to the power flow equations, few theoretical results are available characterizing when such…
The time dependent non-equilibrium radiation diffusion equations are important for solving the transport of energy through radiation in optically thick regimes and find applications in several fields including astrophysics and inertial…
New laboratory measurements using an Electron Beam Ion Trap (EBIT) and an x-ray microcalorimeter are presented for the n=3 to n=2 Fe XVII emission lines in the 15 {\AA} to 17 {\AA} range, along with new theoretical predictions for a variety…