Results 11 to 20 of about 8,079,770 (310)
Natural line profile asymmetry
Physica Scripta, 2022 Abstract The paper discusses the line profile asymmetry of the photon scattering process that arises naturally in quantum electrodynamics (QED). Based on precision spectroscopic experiments conducted on hydrogen atoms, we focus our attention on the two-photon 1s − 2s transition.
A Anikin, T Zalialiutdinov, D Solovyev
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Line Profile Variations in AGN [PDF]
International Astronomical Union Colloquium, 1994 AbstractLine-profile variations in the Seyfert galaxies NGC 5548 and NGC 4593 are discussed. The variations of individual line segments are different from line to line and from outburst to outburst.
W. Kollatschny, M. Dietrich
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Diffraction Line Profiles in the Rietveld Method
, 2020 The present work traces the evolution of the modeling of the diffraction line profiles in the Rietveld method, starting from the early and most schematic description with Gaussian curves to the mos...
P. Scardi
semanticscholar +1 more source
Stark Broadening of N VI Spectral Lines
Universe, 2023 Stark broadening parameters, line widths and shifts, for 15 N VI multiplets are calculated using semiclassical perturbation theory for temperatures from 50,000 K to 2,000,000 K, and perturber density of 1016 cm−3. As perturbers have been taken electrons,
Milan S. Dimitrijević +2 more
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What Sets the Line Profiles in Tidal Disruption Events? [PDF]
, 2017 We investigate line formation in gas that is outflowing and optically thick to electron scattering, as may be expected following the tidal disruption of a star by a supermassive black hole.
Nathaniel Roth, D. Kasen
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Measured Stark widths and shifts in the O IV spectrum [PDF]
Serbian Astronomical Journal, 2003 Stark widths (W) and shifts (d) of 5 prominent triply ionized oxygen (O IV) spectral lines in 3 multiplets have been measured in oxygen plasma at 42 000 K electron temperature using a linear, low-pressure, pulsed arc discharge as an optically thin plasma
Đeniže Stevan +3 more
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Non-Maxwellian Analysis of the Transition-region Line Profiles Observed by the Interface Region Imaging Spectrograph [PDF]
, 2017 We investigate the nature of the spectral line profiles for transition-region (TR) ions observed with the Interface Region Imaging Spectrograph (IRIS).
J. Dudík +4 more
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Extreme Quasars as Distance Indicators in Cosmology
Frontiers in Astronomy and Space Sciences, 2020 Quasars accreting matter at very high rates (known as extreme Population A [xA] quasars, possibly associated with super-Eddington accreting massive black holes) may provide a new class of distance indicators covering cosmic epochs from present day up to ...
Deborah Dultzin +10 more
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Line Profiles in the Bulge of NGC7217 [PDF]
Symposium - International Astronomical Union, 1993 Line-of-sight velocity distributions are becoming increasingly important for our understanding of galactic structure. We present results obtained for the bulge of NGC7217 with a new deconvolution technique.
Konrad Kuijken, Michael R. Merrifield
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First evidence of non-Gaussian solar flare EUV spectral line profiles and accelerated non-thermal ion motion [PDF]
, 2016 The properties of solar flare plasma can be determined from the observation of optically thin lines. The emitting ion distribution determines the shape of the line, with an isothermal Maxwellian ion distribution producing a Gaussian profile. Non-Gaussian
N. Jeffrey, L. Fletcher, N. Labrosse
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