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Related papers: Halpha with Heating by Particle Beams

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We investigate departures from LTE in the line formation of Fe for a number of well-studied late-type stars in different evolutionary stages. A new model of Fe atom was constructed from the most up-to-date theoretical and experimental…

Solar and Stellar Astrophysics · Physics 2015-06-05 Maria Bergemann , Karin Lind , Remo Collet , Zazralt Magic , Martin Asplund

We present a new approach to studies of bubble dynamics in fluids. Relying on particle-based simulations, this method is general and suitable for cases where the commonly used perfect fluid description fails. We study expanding true vacuum…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-14 Marek Lewicki , Ville Vaskonen , Hardi Veermäe

We consider a system of two reaction-diffusion-advection equations describing the one dimensional directed motion of particles with superimposed diffusion and mutual alignment. For this system we show the existence of traveling wave…

Analysis of PDEs · Mathematics 2021-01-19 Heinrich Freistühler , Jan Fuhrmann

The role of turbulence in setting boundary plasma conditions is presently a key uncertainty in projecting to fusion energy reactors. To robustly diagnose edge turbulence, we develop and demonstrate a technique to translate brightness…

We propose a nonlinear self-consistent model of the turbulent non-resonant particle acceleration in solar flares. We simulate temporal evolution of the spectra of charged particles accelerated by strong long-wavelength MHD turbulence taking…

Solar and Stellar Astrophysics · Physics 2009-11-13 A. M. Bykov , G. D. Fleishman

Most of the physical information about astrophysical objects is obtained via the analysis of their electromagnetic spectra. Observed data coupled with radiation transfer models in physical conditions representative of stars, planets,…

Solar and Stellar Astrophysics · Physics 2026-05-29 Maria Bergemann , Richard Hoppe

One of the most severe limitations in particle accelerators and beam transport are non-linear effects. Techniques to study and possibly suppress some of these detrimental effects exist, the most popular are based on particle tracking and…

Accelerator Physics · Physics 2020-06-17 Werner Herr

New observational facilities are becoming increasingly capable of observing reflected light from transiting and directly imaged extrasolar planets. In this study, we provide an analytic framework to interpret observed phase curves,…

Earth and Planetary Astrophysics · Physics 2015-06-03 Nikku Madhusudhan , Adam Burrows

The study of vapor bubble growth following droplet vaporization in a superheated liquid involves research areas such as hydrodynamics, heat transfer, mass transfer, and thermodynamics. The interplay between these multiscale aspects is…

Fluid Dynamics · Physics 2024-04-29 Muhammad Saeed Saleem , Michel Versluis , Guillaume Lajoinie

The present work is the continuation of the investigation of aspects of wave turbulence in preheating we have started in Refs. [1, 2] but considering several classes of inflationary two-fields models. We exhibit the main elements of the…

General Relativity and Quantum Cosmology · Physics 2019-06-04 J. A. Crespo , H. P. de Oliveira

A recent paper states that ultraviolet backradiation from the solar transition region and upper chromosphere strongly affects the degree of ionization of minority stages at the top of the photosphere, i.e., in the temperature minimum of the…

Solar and Stellar Astrophysics · Physics 2015-06-04 R. J. Rutten , H. Uitenbroek

We calculate the Lambda polarization in an exact analytical, rotating model based on parameters extracted from a high resolution (3+1)D Particle-in-Cell Relativistic hydrodynamics calculation. The polarization is attributed to effects from…

Nuclear Theory · Physics 2015-12-09 Yilong Xie , Robert C. Glastad , Laszlo P. Csernai

We study quantum Hall effect within the framework of a newly proposed approach, which captures the principal results of some proposals. This can be established by considering a system of particles living on the non-commutative plane in the…

High Energy Physics - Theory · Physics 2008-11-26 Ahmed Jellal , Youssef Khedif

High-energy astrophysical systems frequently contain collisionless relativistic plasmas that are heated by turbulent cascades and cooled by emission of radiation. Understanding the nature of this radiative turbulence is a frontier of…

High Energy Astrophysical Phenomena · Physics 2020-02-05 Vladimir Zhdankin , Dmitri A. Uzdensky , Gregory R. Werner , Mitchell C. Begelman

Nonthermal relativistic plasmas are ubiquitous in astrophysical systems like pulsar wind nebulae and active galactic nuclei, as inferred from their emission spectra. The underlying nonthermal particle acceleration (NTPA) processes have…

High Energy Astrophysical Phenomena · Physics 2020-04-15 Kai Wong , Vladimir Zhdankin , Dmitri A. Uzdensky , Gregory R. Werner , Mitchell C. Begelman

We present work on H alpha spectral line characteristics in PHOENIX stellar model atmospheres and their comparison to microlensing observations. We examine in detail the H alpha equivalent width (EW) and the line shape characteristics for…

Astrophysics · Physics 2009-11-11 Christine Thurl , Penny D. Sackett , Peter H. Hauschildt

We show that the ''turbulent'' particle spectra found in numerical simulations of the behavior of matter fields during reheating admit a simple interpretation in terms of hydrodynamic models of the reheating period. We predict a particle…

High Energy Physics - Phenomenology · Physics 2016-08-16 Mariana Graña , Esteban Calzetta

A theoretical model is developed by exploiting the variational technique to investigate the evolution of an optical beam inside an optically pumped graded-index fiber amplifier. The variational analysis is a semi-analytical method that…

Optics · Physics 2023-10-24 Anuj P. Lara , Samudra Roy , Govind P. Agrawal

We study a partially ionized hydrogen plasma by means of quantum molecular dynamics, which is based on wave packets. We introduce a new model which distinguishes between free and bound electrons. The free electrons are modelled as Gaussian…

Plasma Physics · Physics 2009-10-30 W. Ebeling , B. Militzer

Turbulent, relativistic nonthermal plasmas are ubiquitous in high-energy astrophysical systems, as inferred from broadband nonthermal emission spectra. The underlying turbulent nonthermal particle acceleration (NTPA) processes have…

High Energy Astrophysical Phenomena · Physics 2025-10-08 Kai W. Wong , Vladimir Zhdankin , Dmitri A. Uzdensky , Gregory R. Werner , Mitchell C. Begelman
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