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Related papers: Full non-LTE spectral line formation I. Setting th…

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Context. Departures from local thermodynamic equilibrium (LTE) distort the calcium abundance derived from stellar spectra in various ways, depending on the lines used and the stellar atmospheric parameters. The collection of atomic data…

Solar and Stellar Astrophysics · Physics 2019-03-13 Y. Osorio , K. Lind , P. S. Barklem , C. Allende Prieto , Oleg Zatsarinny

Older GCE models predict [K/Fe] ratios as much as 1 dex lower than those inferred from stellar observations. Abundances of potassium are mainly based on analyses of the 7698 $\AA$ resonance line, and the discrepancy between models and…

This Report discusses a recently developed concept of Limiting Phase Trajectories (LPTs) providing a unified description of resonant energy transport in a wide range of classical and quantum dynamical systems with constant and time-varying…

Pattern Formation and Solitons · Physics 2016-05-31 Leonid Manevitch , Agnessa Kovaleva , Yuli Starosvetsky

We present three-dimensional (3D) non-local thermodynamic equilibrium (non-LTE) radiative transfer calculations for silicon in the solar photosphere, using an extensive model atom that includes recent, realistic neutral hydrogen collisional…

Solar and Stellar Astrophysics · Physics 2016-09-28 A. M. Amarsi , M. Asplund

Controlling photon mediated energy flow is central to the future of communications, thermal management, and energy harvesting technologies. Recent breakthroughs have revealed that many body systems violating Lorentz reciprocity can sustain…

Optics · Physics 2025-10-16 Sina Jafari Ghalekohneh , Bo Zhao

The influence of departures from local thermodynamic equilibrium (LTE) on neutral sulfur lines is considered. A grid of corrections is proposed to take into account the influence of departures from LTE for neutral sulfur lines in the…

Solar and Stellar Astrophysics · Physics 2025-03-18 S. A. Korotin , K. O. Kiselev

Aiming at testing the validity of our magnesium atomic model and investigating the effects of non-local thermodynamical equilibrium (NLTE) on the formation of the H-band neutral magnesium lines, we derive the differential Mg abundances from…

Solar and Stellar Astrophysics · Physics 2017-01-25 Junbo Zhang , Jianrong Shi , Kaike Pan , Carlos Allende Prieto , Chao Liu

Despite its non-Hermitian nature, the transverse optical beam shift exhibits both real eigenvalues and non-orthogonal eigenstates. To explore this unexpected similarity to typical PT (parity-time)-symmetric systems, we first categorize the…

We derive general formulas for photon and dilepton production rates from an arbitrary non-equilibrated medium from first principles in quantum field theory. At lowest order in the electromagnetic coupling constant, these relate the rates to…

High Energy Physics - Phenomenology · Physics 2009-11-10 Julien Serreau

We study the formation of O I and OH spectral lines in three-dimensional hydrodynamic models of the solar photosphere. The line source function of the O I 777 nm triplet is allowed to depart from local thermodynamic equilibrium (LTE),…

Astrophysics · Physics 2007-05-23 Dan Kiselman , Åke Nordlund

{We aim to demonstrate the effect of atmospheric inhomogeneities on the emergent specific intensity and radiation flux of a spectral line radiation.} {We self-consistently solve the NLTE problem for a two-level atom in a 3D atmosphere using…

Solar and Stellar Astrophysics · Physics 2019-01-08 A. Tichý , J. Kubát

A self-consistent approach to nonequilibrium radiation temperature is introduced using the distribution of the energy over states. We begin rigorously with ensembles of Hilbert spaces and end with practical examples based mainly on the far…

Statistical Mechanics · Physics 2009-11-07 Christopher Essex , Dallas C. Kennedy , R. Stephen Berry

Accurate spectroscopic lithium abundances are essential in addressing a variety of open questions, such as the origin of a uniform lithium content in the atmospheres of metal-poor stars (Spite plateau) or the existence of a correlation…

Solar and Stellar Astrophysics · Physics 2020-07-01 A. Mott , M. Steffen , E. Caffau , K. G. Strassmeier

The vast majority of recent advances in the field of numerical radiative transfer relies on approximate operator methods better known in astrophysics as Accelerated Lambda-Iteration (ALI). A superior class of iterative schemes, in term of…

Astrophysics · Physics 2021-05-12 F. Paletou , L. Leger

In self-gravitating stars, two dimensional or geophysical flows and in plasmas, long range interactions imply a lack of additivity for the energy; as a consequence, the usual thermodynamic limit is not appropriate. However, by contrast with…

Statistical Mechanics · Physics 2009-11-13 Freddy Bouchet , Julien Barré , Antoine Venaille

We solve analytically the out-of-equilibrium initial stage that follows the injection of a radially finite electron beam into a plasma at rest and test it against particle-in-cell simulations. For initial large beam edge gradients and not…

Plasma Physics · Physics 2009-11-11 M. -C. Firpo , A. F. Lifschitz , E. Lefebvre , C. Deutsch

In an effort to estimate the largely unknown effects of photospheric temperature fluctuations on spectroscopic abundance determinations, we have studied the problem of LTE line formation in the inhomogeneous solar photosphere based on…

Astrophysics · Physics 2009-11-07 M. Steffen , H. Holweger

Non-local thermodynamic equilibrium (NLTE) effects in diagnostically important solar Fe I lines are important due to the strong sensitivity of Fe I to ionizing UV radiation, which may lead to a considerable under-population of the Fe I…

Solar and Stellar Astrophysics · Physics 2015-10-21 René Holzreuter , Sami K. Solanki

We study a number of issues related to the emission and absorption radiation by non-relativistic electrons within the framework of a Lorentz-breaking electrodynamics in (3+1) dimensions. Our main results concern how Planck-like spectrum law…

High Energy Physics - Theory · Physics 2009-01-14 J. M. Fonseca , A. H. Gomes , W. A. Moura-Melo

Detailed non-LTE calculations for red supergiant stars are presented to investigate the influence of NLTE on the formation of atomic iron and titanium lines in the J-band. With their enormous brightness at J-band red supergiant stars are…

Solar and Stellar Astrophysics · Physics 2015-06-04 Maria Bergemann , Rolf-Peter Kudritzki , Bertrand Plez , Ben Davies , Karin Lind , Zach Gazak
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