Related papers: Revisiting He-like X-ray Emission Line Plasma Diag…
Atomic data and plasma models play a crucial role in the diagnosis and interpretation of astrophysical spectra, thus influencing our understanding of the universe. In this investigation we present a systematic comparison of the leading…
Over the last 3 yrs, the Galactic center (GC) region has been monitored with the Chandra X-Ray Observatory. With 11 Chandra observations through 2002 June, the total effective exposure reaches ~590 ks, providing significant photon…
We present a new model for computing consistently the line and continuum emission from galaxies, based on a combination of recent population synthesis and photoionization codes. We use effective parameters to describe the HII regions and…
Photoionization modelling allows to follow the transport, the emergence, and the absorption of photons taking into account all important processes in nebular plasmas. Such modelling needs the spatial distribution of density, chemical…
We discuss new methods of measuring and interpreting the forbidden-to-intercombination line ratios of helium-like triplets in the X-ray spectra of O-type stars, including accounting for the spatial distribution of the X-ray emitting plasma…
We examine the conditions of the plasma along a sample of 'classical' Herbig-Haro jets located in the Orion and Vela star forming regions, through combined optical-infrared spectral diagnostics. Our sample includes HH 111, HH 34, HH 83, HH…
Collective effects, such as waves and instabilities, are integral to our understanding of most plasma phenomena. We have been able to study these in ultracold neutral plasmas by shaping the initial density distribution through spatial…
We extend our time-dependent hydrogen ionization simulations of diffuse ionized gas to include metals important for collisional cooling and diagnostic emission lines. The combination of heating from supernovae and time-dependent collisional…
We present a method for including steady-state gas flows in the plasma physics code Cloudy, which was previously restricted to modeling static configurations. The numerical algorithms are described in detail, together with an example…
We present the results of high resolution spectroscopy of the prototype polar AM Herculis observed with Chandra High Energy Transmission Grating. The X-ray spectrum contains hydrogen-like and helium-like lines of Fe, S, Si, Mg, Ne and O…
This paper outlines a way to determine the ICF using only infrared data. We identify four line pairs, [NeIII] 36$\micron$/[NeII] 12.8$\micron$, [NeIII]~15.6$\micron$ /[NeII] 12.8$\micron$, [ArIII] 9$\micron$/[ArII] 6.9$\micron$, and [ArIII]…
For the first time the emission of the radiative dissociation continuum of the hydrogen molecule ($a^{3}\Sigma_{g}^{+} \to b^{3}\Sigma_{u}^{+}$ electronic transition) is proposed to be used as a source of information for the spectroscopic…
We present a theoretical and experimental investigation of homonuclear ionizing collisions of laser-cooled metastable helium atoms, considering both the fermionic He-3 and bosonic He-4 isotope. The theoretical description combines quantum…
There has been a growing request from the X-ray astronomy community for a quantitative estimate of systematic uncertainties originating from the atomic data used in plasma codes. Though there have been several studies looking into atomic…
We present new collisional-radiative models (CRMs) for helium in the quiescent solar corona, and predict the emissivities of the He and He$^+$ lines to be observed by DKIST, Solar Orbiter, and Proba-3. We discuss in detail the rates we…
The uniformity of the helium-to-hydrogen abundance ratio in X-ray emitting intracluster medium (ICM) is one of the commonly adopted assumptions in X-ray analyses of galaxy clusters and cosmological constraints derived from these…
Aims: We generate theoretical ultraviolet and extreme-ultraviolet emission line ratios for O IV and show their strong versatility as electron temperature and density diagnostics for astrophysical plasmas. Methods: Recent fully relativistic…
The population of meta-stable levels is key to high precision density diagnostics of astrophysical plasmas. In photo-ionized plasmas, density is used to infer the distance from the ionizing source, which is otherwise difficult to obtain.…
Hydrodynamic simulations predict that a significant fraction of the gas in the current Universe is in the form of high temperature, highly ionized plasma emitting and absorbing primarily in the soft X-ray and UV bands, dubbed the Warm-Hot…
Accounting for nebular emission when modeling galaxy spectral energy distributions (SEDs) is important, as both line and continuum emission can contribute significantly to the total observed flux. In this work, we present a new nebular…