Related papers: The role of some collisional processes in AGNs: ra…
(*** abridged ***) Context: The wings of Balmer lines are often used as effective temperature diagnostics for late-type stars under the assumption they form in local thermodynamic equilibrium. Aims: Our goal is to investigate the non-LTE…
We analyze the ratios of the broad hydrogen Balmer emission lines (from H\alpha to H\epsilon) in the context of estimating the physical conditions in the broad line region (BLR) of active galactic nuclei (AGN). The Balmer emission lines are…
Many large scale numerical simulations of astrophysical plasmas must also reproduce the hydrogen ionization and the resulting emission spectrum, in some cases quite accurately. We describe a compact model hydrogen atom that can be readily…
The chemi-ionization (CI) processes in atom-Rydberg-atom collisions are investigated in this contribution. The rate coefficients for CI processes in $\textrm{Li}^{*}(n) + \textrm{Na}$, $\textrm{Li}^{*}(n) + \textrm{Li}$, $\textrm{Na}^{*}(n)…
New X-ray observatories (Chandra and XMM-Newton) are providing a wealth of high-resolution X-ray spectra in which hydrogen- and helium-like ions are usually strong features. We present results from a new collisional-radiative plasma code,…
Spectral lines emitted by plasmas provide information about the thermodynamic conditions, the degree of randomness or the interactions prevailing in the medium. Collisions by plasma electrons penetrating the extent of bound-electron…
In this work we investigate the properties of the broad emission line components in the Balmer series of a sample of Type 1 Active Galactic Nuclei (AGN). Using the Boltzmann Plot method as a diagnostic tool for physical conditions in the…
Atomic hydrogen masers occur in recombination plasmas in sufficiently dense HII regions. These hydrogen recombination line (HRL) masers have been observed in a handful of objects to date and the analysis of the atomic physics involved has…
We present analytical expressions for direct evaluation of $\ell$-mixing rate coefficients in proton-excited hydrogen atom collisions and describe a software package for efficient numerical evaluation of the collisional rate coefficients.…
Quantitative spectroscopy of molecular hydrogen has generated substantial demand, leading to the accumulation of diverse elementary-process data encompassing radiative transitions, electron-impact transitions, predissociations, and…
Energy-changing electron-hydrogen atom collisions are crucial to regulating the energy balance in astrophysical and laboratory plasmas and relevant to the formation of stellar atmospheres, recombination in H-II clouds, primordial…
Thorough modeling of the physics involved in liquid argon calorimetry is essential for accurately predicting the performance of DUNE and optimizing its design and analysis pipeline. At the fundamental level, it is essential to quantify the…
Ultracold plasmas are formed by photo-exciting clouds of cold atoms and molecules near the ionization threshold. They explore a new region of plasma physics and display effects of strong coupling, which is characterized by a ratio of…
Recent experimental results about the formation of molecular hydrogen on astrophysically relevant surfaces under conditions close to those encountered in the interstellar medium are analyzed using rate equations. The parameters of the rate…
A new analysis technique for the inference of degree of dissociation of weakly collisional hydrogen plasmas was developed and tested with an experiment. Neutrals in low temperature plasmas are critical to a wide range of plasma-based…
Using a well known method for laboratory plasma diagnostic, the Boltzmann-plot, we discuss the physical properties in Broad Line Region (BLR) of Active Galactic Nuclei (AGN). We apply the Boltzmann-plot method to Balmer lines on a sample of…
Recently, rapid observational and theoretical progress has established that black holes (BHs) play a decisive role in the formation and evolution of individual galaxies as well as galaxy groups and clusters. In particular, there is…
Thanks to the new generation of X-ray satellites such as Chandra and XMM, high resolution and high sensitivity spectra are available. In particular, for the first time, the three most intense lines (resonance, intercombination and…
In this work we analyze a sample of AGN spectra, selected from the 6th Data Release of the Sloan Digital Sky Survey, exploiting a generalized technique of line profile analysis, designed to take into account the whole profiles of their…
Active Galactic Nuclei (AGN) in cosmological simulations generate explosive feedback that regulates star formation in massive galaxies, modifying the gas phase structure out to large distances. Here, we explore the direct effects that AGN…