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Related papers: An Updated Formalism For Line-Driven Radiative Acc…

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We employ first-principles, fully kinetic particle-in-cell simulations to investigate magnetic field-line curvature in magnetically dominated turbulent plasmas and its role in particle acceleration through curvature-drift motion along the…

High Energy Astrophysical Phenomena · Physics 2025-11-14 Samuel Sebastian , Luca Comisso

New numerical models of line-driven stellar winds of late O stars are presented. Statistical equilibrium (NLTE) equations of the most abundant elements are solved. Properly obtained occupation numbers are used to calculate consistent…

Astrophysics · Physics 2009-11-10 Jiri Krticka , Jiri Kubat

The power flow equations are fundamental to power system planning, analysis, and control. However, the inherent non-linearity and non-convexity of these equations present formidable obstacles in problem-solving processes. To mitigate these…

Optimization and Control · Mathematics 2024-11-15 Paprapee Buason , Sidhant Misra , Jean-Paul Watson , Daniel K. Molzahn

The hypothesis that CAK-type line driving is responsible for the large observed Wolf-Rayet (W-R) mass-loss rates has been called into question in recent theoretical studies. The purpose of this paper is to reconsider the plausibility of…

Astrophysics · Physics 2009-11-13 Andrew J. Onifer , Kenneth G. Gayley

The nonlinear mass is a characteristic scale in halo formation that has wide-ranging applications across cosmology. Naively, computing it requires repeated numerical integration to calculate the variance of the power spectrum on different…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-04 Alex Krolewski , Zachary Slepian

The fine structure constant, $\alpha$, sets the strength of the electromagnetic force. The Standard Model of particle physics provides no explanation for its value, which could potentially vary. The wavelengths of stellar absorption lines…

Solar and Stellar Astrophysics · Physics 2022-11-30 Michael T. Murphy , Daniel A. Berke , Fan Liu , Chris Flynn , Christian Lehmann , Vladimir A. Dzuba , Victor V. Flambaum

In an attempt to understand the extraordinarily small mass-loss rates of late-type O dwarfs, mass fluxes in the relevant part of (T_{eff}, g)-space are derived from first principles using a previously-described code for constructing moving…

Solar and Stellar Astrophysics · Physics 2015-05-14 L. B. Lucy

The interplay between the superradiant emission of a cloud of cold two-level atoms and the radiation pressure force is discussed. Using a microscopic model of coupled atomic dipoles driven by an external laser, the radiation field and the…

Radiation pressure can be dynamically important in star-forming environments such as ultra-luminous infrared and submillimeter galaxies. Whether and how radiation drives turbulence and bulk outflows in star formation sites is still unclear.…

Astrophysics of Galaxies · Physics 2015-10-15 Benny Tsz-Ho Tsang , Milos Milosavljevic

Mapping of multiple lines such as the fine-structure emission from [CII] (157.7 $\mu \text{m}$), [OIII] (52 \& 88.4 $\mu \text{m}$), and rotational emission lines from CO are of particular interest for upcoming line intensity mapping (LIM)…

For a long time transverse and longitudinal optical forces are used for non-contact and noninvasive manipulation of small individual particles. The following question arises: What is the impact of these forces on the ensemble of thousand…

Optics · Physics 2021-05-26 Lubomir Kovachev

The effect of gravitational microlensing on the intensity of gravitational radiation as it propagates through an inhomogeneous medium containing small-scale structure is considered. Lensing by both stars and a power law spectrum of density…

Astrophysics · Physics 2009-11-11 Jean-Pierre Macquart

Context. Current implementations of mass loss for hot, massive stars in stellar evolution models include a sharp increase in mass loss when blue supergiants become cooler than Teff 20-22kK. This drastic mass-loss jump has been motivated by…

In this paper, the interaction of a 1064 nm continuum-wave laser with inductively-coupled plasma generated in a fluorescent light bulb has been studied both experimentally and theoretically. The absorption coefficients pertaining to the…

Plasma Physics · Physics 2020-02-17 M. Fatih Yilmaz , M. Elif Tanriseven , Edgar Obonyo , Y. Danisman

Galactic outflows are believed to play an important role in regulating star formation in galaxies, but estimates of the outflowing mass and momentum have historically been based on uncertain assumptions. Here, we measure the mass, momentum,…

Astrophysics of Galaxies · Physics 2017-06-28 John Chisholm , Christy A. Tremonti , Claus Leitherer , Yanmei Chen

We present new or improved methods for calculating NLTE, line-blanketed model atmospheres for hot stars with winds (spectral types A to O), with particular emphasis on a fast performance. These methods have been implemented into a previous,…

Astrophysics · Physics 2009-11-10 J. Puls , M. A. Urbaneja , R. Venero , T. Repolust , U. Springmann , A. Jokuthy , M. R. Mokiem

The relation between the shape of the force driving a turbulent flow and the upper bound on the dimensionless dissipation factor $\beta$ is presented. We are interested in non-trivial (more than two wave numbers) forcing functions in a…

Fluid Dynamics · Physics 2011-09-16 B. Rollin , Y. Dubief , C. R. Doering

An improved formulation for the X-factor is proposed. The statement that the velocity-integrated radiation temperature of the $\COone$ line, $I(\CO)$, ``counts'' optically thick clumps is quantified using the formalism of \citet{Martin84}…

Astrophysics · Physics 2008-11-26 W. F. Wall

We present a new method for using measured X-ray emission line fluxes from O stars to determine the shock-heating rate due to instabilities in their radiation-driven winds. The high densities of these winds means that their embedded shocks…

Solar and Stellar Astrophysics · Physics 2015-06-22 David H. Cohen , Zequn Li , Kenneth G. Gayley , Stanley P. Owocki , Jon O. Sundqvist , Veronique Petit , Maurice A. Leutenegger

Massive ($M >30\,$M$_{\odot}$) stars exhibit luminosities that are near the Eddington-limit for electron scattering causing the increase in opacity associated with iron at $T\approx180,000\,$K to trigger supersonic convection in their outer…

Solar and Stellar Astrophysics · Physics 2020-10-21 William Schultz , Lars Bildsten , Yan-Fei Jiang
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