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We study the relaxation dynamics of laser-excited non-equilibrium electron distributions in the valence- and conduction band of a dielectric. We apply Boltzmann collision integrals to trace the influence of different scattering mechanisms…

Statistical Mechanics · Physics 2023-04-28 Nils Brouwer , Steffen Hirtle , Baerbel Rethfeld

The multi-fluid modelling of high-frequency waves in partially ionized plasmas has shown that the behavior of magnetohydrodynamics waves in the linear regime is heavily influenced by the collisional interaction between the different species…

Solar and Stellar Astrophysics · Physics 2018-04-04 David Martínez-Gómez , Roberto Soler , Jaume Terradas

The broadening of the hydrogen lines during flares is thought to result from increased charge (electron, proton) density in the flare chromosphere. However, disagreements between theory and modeling prescriptions have precluded an accurate…

We have used the free expansion of ultracold neutral plasmas as a time-resolved probe of electron temperature. A combination of experimental measurements of the ion expansion velocity and numerical simulations characterize the crossover…

Atomic Physics · Physics 2009-11-13 P. Gupta , S. Laha , C. E. Simien , H. Gao , J. Castro , T. Pohl , T. C. Killian

We perform nonadiabatic simulations of warm dense aluminum based on the electron-force field (EFF) variant of wave-packet molecular dynamics. Comparison of the static ion-ion structure factor with density functional theory (DFT) is used to…

Plasma Physics · Physics 2020-12-08 Ryan A. Davis , W. A. Angermeier , R. Hermsmeier , Thomas G. White

We study the X-ray spectra of tenuous, two-temperature accretion flows using a model involving an exact, Monte Carlo computation of the global Comptonization effect as well as general relativistic description of both the flow structure and…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Andrzej Niedzwiecki , Agnieszka Stepnik , Fu-Guo Xie

We report on an X-ray flare detected on the active binary system II~Pegasi with the Swift telescope. The trigger had a 10-200 keV luminosity of 2.2$\times10^{32}$ erg s$^{-1}$-- a superflare, by comparison with energies of typical stellar…

Astrophysics · Physics 2008-11-26 R. A. Osten , S. Drake , J. Tueller , J. Cummings , M. Perri , A. Moretti , S. Covino

Aims: We want to probe the physics of fast collision-less shocks in supernova remnants. In particular, we are interested in the non-equilibration of temperatures and particle acceleration. Specifically, we aim to measure the oxygen…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Sjors Broersen , Jacco Vink , Marco Miceli , Fabrizio Bocchino , Gilles Maurin , Anne Decourchelle

The magnetic processes associated with the non-thermal broadening of optically thin emission lines appear to carry enough energy to heat the corona and accelerate the solar wind. We investigate whether non-thermal motions in cool stars…

Solar and Stellar Astrophysics · Physics 2023-06-28 S. Boro Saikia , T. Lueftinger , V. S. Airapetian , T. Ayres , M. Bartel , M. Guedel , M. Jin , K. G. Kislyakova , P. Testa

To examine the evolution of giant molecular clouds in the stream of a hot plasma we performed two-dimensional hydrodynamical simulations that take full account of self-gravity, heating and cooling effects and heat conduction by electrons.…

Astrophysics · Physics 2009-11-13 W. Vieser , G. Hensler

To better model the efficient production of cosmic rays (CRs) in supernova remnants (SNRs) with the associated coupling between CR production and SNR dynamics, we have generalized an existing cr-hydro-NEI code (i.e., Ellison et al. 2012) to…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Shiu-Hang Lee , Donald C. Ellison , Shigehiro Nagataki

We model the broad-band emission from SNR RX J1713.7-3946 including, for the first time, a consistent calculation of thermal X-ray emission together with non-thermal emission in a nonlinear diffusive shock acceleration (DSA) model. Our…

High Energy Astrophysical Phenomena · Physics 2015-05-14 Donald C. Ellison , Daniel J. Patnaude , Patrick Slane , John Raymond

The single-degenerate scenario for Type Ia supernovae (SNe Ia) should yield metal-rich ejecta that enclose some stripped material from the non-degenerate H-rich companion star. We present a large grid of non-local thermodynamic equilibrium…

Solar and Stellar Astrophysics · Physics 2020-07-01 Luc Dessart , Douglas C. Leonard , Jose L. Prieto

We present simulations of cosmic reionization and reheating from $z=18$ to $z=5$, investigating the role of stars (emitting soft UV-photons), nuclear black holes (BHs, with power-law spectra), X-ray binaries (XRBs, with hard X-ray dominated…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-16 Marius B. Eide , Benedetta Ciardi , Luca Graziani , Philipp Busch , Yu Feng , Tiziana Di Matteo

An accurate treatment of the multiphase interstellar medium (ISM) in hydrodynamic galaxy simulations requires that we follow not only the thermal evolution of the gas, but also the evolution of its chemical state, including its molecular…

Astrophysics of Galaxies · Physics 2015-06-18 Alexander J. Richings , Joop Schaye , Benjamin D. Oppenheimer

In a previous paper we have described a technique to derive constraints on the differential emission measure (DEM) distribution, a measure of the temperature distribution, of collisionally ionized hot plasmas from their X-ray emission line…

Astrophysics · Physics 2009-11-10 Patrick S. Wojdowski , Norbert S. Schulz

Supernovae (SNe) with strong interactions with circumstellar material (CSM) are promising candidate sources of high-energy neutrinos and gamma rays, and have been suggested as an important contributor to Galactic cosmic rays beyond 1 PeV.…

High Energy Astrophysical Phenomena · Physics 2019-03-27 Kohta Murase , Anna Franckowiak , Keiichi Maeda , Raffaella Margutti , John F. Beacom

In this study, we examine thermal conductivity and the thermal Hall effect in electron-ion plasmas relevant to hot neutron stars, white dwarfs, and binary neutron star mergers, focusing on densities found in the outer crusts of neutron…

High Energy Astrophysical Phenomena · Physics 2024-11-18 Arus Harutyunyan , Armen Sedrakian

Using the thermal quasiparticle random phase approximation, we study the process of neutrino and antineutrino capture on hot nuclei in supernova environments. For the sample nuclei $^{56}$Fe and $^{82}$Ge we perform a detailed analysis of…

Nuclear Theory · Physics 2015-10-22 Alan A. Dzhioev , A. I. Vdovin , J. Wambach

We perform particle-in-cell simulations of perpendicular nonrelativistic collisionless shocks to study electron heating and pre-acceleration for parameters that permit extrapolation to the conditions at young supernova remnants. Our…

High Energy Astrophysical Phenomena · Physics 2017-10-04 Artem Bohdan , Jacek Niemiec , Oleh Kobzar , Martin Pohl