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John F. Kielkopf - One of the best experts on this subject based on the ideXlab platform.
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theoretical profiles of the mg Resonance Lines perturbed by collisions with he
Astronomy and Astrophysics, 2016Co-Authors: N. F. Allard, Grégoire Guillon, V. A. Alekseev, John F. KielkopfAbstract:The effects of collision broadening by He are central to understanding the opacity of cool stellar atmospheres. Aims. DZ white dwarfs show metal Lines which are, in many cases, believed to come from some rocky material, a remnant of a former exoplanetary system. The analysis of the Mg + Resonance Lines is a valuable method to determine the chemical abundances in these systems. Methods. Unified profiles of the strongest of the UV Lines of Mg + have been calculated in the semi-classical approach using very recent ab initio potential energies. Results. We present the first theoretical line profile calculations of the Resonance Lines of Mg + that have been perturbed by helium in physical conditions of atmospheres in helium-rich white dwarfs with metal traces.
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Theoretical profiles of the Mg+ Resonance Lines perturbed by collisions with He
Astronomy & Astrophysics, 2016Co-Authors: N. F. Allard, Grégoire Guillon, V. A. Alekseev, John F. KielkopfAbstract:The effects of collision broadening by He are central to understanding the opacity of cool stellar atmospheres. Aims. DZ white dwarfs show metal Lines which are, in many cases, believed to come from some rocky material, a remnant of a former exoplanetary system. The analysis of the Mg + Resonance Lines is a valuable method to determine the chemical abundances in these systems. Methods. Unified profiles of the strongest of the UV Lines of Mg + have been calculated in the semi-classical approach using very recent ab initio potential energies. Results. We present the first theoretical line profile calculations of the Resonance Lines of Mg + that have been perturbed by helium in physical conditions of atmospheres in helium-rich white dwarfs with metal traces.
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theoretical profiles of light alkali Resonance Lines for brown dwarf atmosphere conditions
Astronomy and Astrophysics, 2005Co-Authors: N. F. Allard, F Allard, John F. KielkopfAbstract:The analysis of the far wings of Resonance Lines of alkali elements in brown dwarf spectra requires their accurate determination. A unified theory of collisional line profiles has been applied for the evaluation of absorption profiles of alkalis perturbed by helium and molecular hydrogen. The study of the dependence on temperature of the far wings of Li-He and Li-H2 collisional profiles is reported.
N. F. Allard - One of the best experts on this subject based on the ideXlab platform.
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theoretical profiles of the mg Resonance Lines perturbed by collisions with he
Astronomy and Astrophysics, 2016Co-Authors: N. F. Allard, Grégoire Guillon, V. A. Alekseev, John F. KielkopfAbstract:The effects of collision broadening by He are central to understanding the opacity of cool stellar atmospheres. Aims. DZ white dwarfs show metal Lines which are, in many cases, believed to come from some rocky material, a remnant of a former exoplanetary system. The analysis of the Mg + Resonance Lines is a valuable method to determine the chemical abundances in these systems. Methods. Unified profiles of the strongest of the UV Lines of Mg + have been calculated in the semi-classical approach using very recent ab initio potential energies. Results. We present the first theoretical line profile calculations of the Resonance Lines of Mg + that have been perturbed by helium in physical conditions of atmospheres in helium-rich white dwarfs with metal traces.
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Theoretical profiles of the Mg+ Resonance Lines perturbed by collisions with He
Astronomy & Astrophysics, 2016Co-Authors: N. F. Allard, Grégoire Guillon, V. A. Alekseev, John F. KielkopfAbstract:The effects of collision broadening by He are central to understanding the opacity of cool stellar atmospheres. Aims. DZ white dwarfs show metal Lines which are, in many cases, believed to come from some rocky material, a remnant of a former exoplanetary system. The analysis of the Mg + Resonance Lines is a valuable method to determine the chemical abundances in these systems. Methods. Unified profiles of the strongest of the UV Lines of Mg + have been calculated in the semi-classical approach using very recent ab initio potential energies. Results. We present the first theoretical line profile calculations of the Resonance Lines of Mg + that have been perturbed by helium in physical conditions of atmospheres in helium-rich white dwarfs with metal traces.
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theoretical profiles of light alkali Resonance Lines for brown dwarf atmosphere conditions
Astronomy and Astrophysics, 2005Co-Authors: N. F. Allard, F Allard, John F. KielkopfAbstract:The analysis of the far wings of Resonance Lines of alkali elements in brown dwarf spectra requires their accurate determination. A unified theory of collisional line profiles has been applied for the evaluation of absorption profiles of alkalis perturbed by helium and molecular hydrogen. The study of the dependence on temperature of the far wings of Li-He and Li-H2 collisional profiles is reported.
G. Severino - One of the best experts on this subject based on the ideXlab platform.
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Collisional broadening and shift of the alkali Resonance Lines
Solar Physics, 1991Co-Authors: V. Andretta, M. T. Gomez, G. SeverinoAbstract:We use the 6-8-12 interatomic potential, with a suitable scaling for the relevant atomic radii, to reproduce the measured broadening and shift of the alkali Resonance Lines perturbed by noble gases, at temperatures of ∼ 500 K. Then, using the fit to the data with helium and neon as perturbers, we compute new values for the broadening and shift of the alkali Resonance Lines due to atomic hydrogen, at the temperature of 5000 K, which are of interest in the analysis of solar and stellar spectra, and discuss the reliability of these results.
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Collisional broadening and shift of the alkali Resonance Lines
Solar Physics, 1991Co-Authors: V. Andretta, M. T. Gomez, G. SeverinoAbstract:We use the 6-8-12 interatomic potential, with a suitable scaling for the relevant atomic radii, to reproduce the measured broadening and shift of the alkali Resonance Lines perturbed by noble gases, at temperatures of ∼ 500 K.
William L. Rowan - One of the best experts on this subject based on the ideXlab platform.
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Observation of Pd-like Resonance Lines through Pt 32+ and Zn-like Resonance Lines of Er 38+ and Hf 42+
Journal of the Optical Society of America B, 1993Co-Authors: Jack Sugar, Victor Kaufman, William L. RowanAbstract:Spectra of highly ionized Er, Yb, Hf, W, and Pt were observed by injecting these elements into the plasma of the TEXT tokamak. Resonance Lines of the 4d10–4d94f transition array in the Pd i isoelectronic sequence were identified by comparison with plots of observed-minus-calculated transition energies. These plots were based on data previously known through Ho21+. They were fitted to low-order polynomials that permitted accurate predictions of wavelengths to Bi37+. In addition, Resonance Lines of Zn-like Er38+ and Hf42+ were observed.
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observation of pd like Resonance Lines through pt 32 and zn like Resonance Lines of er 38 and hf 42
Journal of The Optical Society of America B-optical Physics, 1993Co-Authors: Jack Sugar, Victor Kaufman, William L. RowanAbstract:Spectra of highly ionized Er, Yb, Hf, W, and Pt were observed by injecting these elements into the plasma of the TEXT tokamak. Resonance Lines of the 4d10–4d94f transition array in the Pd i isoelectronic sequence were identified by comparison with plots of observed-minus-calculated transition energies. These plots were based on data previously known through Ho21+. They were fitted to low-order polynomials that permitted accurate predictions of wavelengths to Bi37+. In addition, Resonance Lines of Zn-like Er38+ and Hf42+ were observed.
V. Andretta - One of the best experts on this subject based on the ideXlab platform.
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Collisional broadening and shift of the alkali Resonance Lines
Solar Physics, 1991Co-Authors: V. Andretta, M. T. Gomez, G. SeverinoAbstract:We use the 6-8-12 interatomic potential, with a suitable scaling for the relevant atomic radii, to reproduce the measured broadening and shift of the alkali Resonance Lines perturbed by noble gases, at temperatures of ∼ 500 K. Then, using the fit to the data with helium and neon as perturbers, we compute new values for the broadening and shift of the alkali Resonance Lines due to atomic hydrogen, at the temperature of 5000 K, which are of interest in the analysis of solar and stellar spectra, and discuss the reliability of these results.
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Collisional broadening and shift of the alkali Resonance Lines
Solar Physics, 1991Co-Authors: V. Andretta, M. T. Gomez, G. SeverinoAbstract:We use the 6-8-12 interatomic potential, with a suitable scaling for the relevant atomic radii, to reproduce the measured broadening and shift of the alkali Resonance Lines perturbed by noble gases, at temperatures of ∼ 500 K.