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Relevant uncertainties on theoretical atomic data are vital to determine the accuracy of plasma diagnostics in a number of areas including in particular the astrophysical study. We present a new calculation of the uncertainties on the…

High Energy Astrophysical Phenomena · Physics 2022-01-19 Liyi Gu , Chintan Shah , Ruitian Zhang

This paper is concerned with two rather basic phenomena: the incoherent fluorescence spectrum of an atom driven by an intense laser field and the coupling of the atom to the (empty) modes of the radiation field. The sum of the many-photon…

Quantum Physics · Physics 2007-05-23 Ulrich D. Jentschura , Joerg Evers , Christoph H. Keitel

We calculate the self-energy and the vertex radiative corrections to the effect of parity nonconservation in heavy atoms. The sum of the corrections is of the form ${\cal A}\ln(\lambda_C/r_0)+{\calB}$, where ${\cal A}$ and ${\cal B}$ are…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. I. Milstein , O. P. Sushkov , I. S. Terekhov

Opacity determines radiation transport through material media. In a plasma source the primary contributors to atomic opacity are bound-bound line transitions and bound-free photoionization into the continuum. We review the theoretical…

Solar and Stellar Astrophysics · Physics 2023-03-08 Anil Pradhan

Energy levels and radiative rates are reported for transitions in Br-like W XL, calculated with the general-purpose relativistic atomic structure package ({\sc grasp}). Configuration interaction (CI) has been included among 46…

Atomic Physics · Physics 2015-06-18 KM Aggarwal , FP Keenan

In the Super-Transition-Array statistical method for the computation of radiative opacity of hot dense matter, the moments of the absorption or emission features involve partition functions with reduced degeneracies, occurring through the…

Atomic Physics · Physics 2024-05-14 Jean-Christophe Pain , Brian Wilson

G.~Hazak and J.~Kurzweil discovered a method of configurational resolution of transition arrays for the Super Transition Arrays approach to the bound-bound opacity calculation. Their method is based on the representation of the…

Plasma Physics · Physics 2025-11-04 Evgeniya Arapova , Yulia Koryakina , Mikhail Vronskiy

A full symmetry classification is given for models of energy transport in radiant plasma when the mass density is spatially variable and the diffusivity is nonlinear. A systematic search for conservation laws also leads to some potential…

Mathematical Physics · Physics 2015-06-18 P. Broadbridge , N. M. Ivanova

We develop a method of analyzing radio frequency spectral line observations to derive data on the temperature, density, velocity, and molecular abundance of the emitting gas. The method incorporates a radiative transfer code with a new…

Astrophysics · Physics 2009-11-10 Eric Keto , George B. Rybicki , Edwin A. Bergin , Rene Plume

The effect of autoionizing resonances in atomic systems and processes is reviewed. Theoretical framework for treating resonances in the coupled channel approximation using the R-matrix method, as well as approximations related to plasma…

High Energy Astrophysical Phenomena · Physics 2024-05-16 Anil Pradhan

Atomic line opacities play a crucial role in stellar astrophysics. They strongly modify the radiative transfer in stars, therefore impacting their physical structure. Ultimately, most of our knowledge of stellar population systems (stars,…

Solar and Stellar Astrophysics · Physics 2015-06-19 Lucimara Martins , Paula Coelho , Anderson Caproni , Roberto Vitoriano

Lanthanide elements play important roles as an opacity source in the ejected material from neutron star mergers. Accurate and complete atomic data are necessary to evaluate the opacities and to analyze the observed data. In this paper, we…

Atomic Physics · Physics 2020-05-13 Laima Radžiūtė , Gediminas Gaigalas , Daiji Kato , Pavel Rynkun , Masaomi Tanaka

Seismology of stars is strongly developing. To address this question we have formed an international collaboration OPAC to perform specific experimental measurements, compare opacity calculations and improve the opacity calculations in the…

Quantum corrections can be important for diffusion and the melting temperature of dense plasmas in compact astrophysical objects, particulary white dwarfs and neutron stars. Typically ions in these systems are modeled classically, but…

Solar and Stellar Astrophysics · Physics 2015-03-19 Justin Mason

We calculate single atom heating rates in a far detuned optical lattice, in connection with recent experiments. We first derive a master equation, including a realistic atomic internal structure and a quantum treatment of the atomic motion…

Quantum Gases · Physics 2015-05-18 Fabrice Gerbier , Yvan Castin

For high temperatures and densities, stellar opacities obtained from the Opacity Project (OP) were smaller than those obtained from the OPAL project. Iglesias and Rogers [Ap.J. v443, 469 (1995)] suggested that the discrepancy was due to the…

Astrophysics · Physics 2009-11-10 N. R. Badnell , M. J. Seaton

Time dependent numerical simulations of the K ALPHA complex of Fe XXV are carried out as a function of temperature/density/radiation field variations in high-temperature astrophysical and laboratory plasmas. In addition to several well…

Astrophysics · Physics 2008-11-26 Justin Oelgoetz , Anil K. Pradhan

We describe our implementation of an extremely detailed model atom of singly ionized iron for NLTE computations in static and moving astrophysical plasmas. Our model atom includes 617 levels, 13675 primary permitted transitions and up to…

Astrophysics · Physics 2015-06-24 Peter H. Hauschildt , E. Baron

The Petersen diagram is a frequently used tool to constrain model parameters such as metallicity of radial double-mode pulsators. In this diagram the period ratio of the radial first overtone to the fundamental mode, P_1/P_0, is plotted…

Astrophysics · Physics 2008-11-26 P. Lenz , A. A. Pamyatnykh , M. Breger

The inference of the underlying state of the plasma in the solar chromosphere remains extremely challenging because of the nonlocal character of the observed radiation and plasma conditions in this layer. Inversion methods allow us to…

Solar and Stellar Astrophysics · Physics 2019-03-06 J. de la Cruz Rodríguez , J. Leenaarts , S. Danilovic , H. Uitenbroek