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Related papers: Firehose constraints for the solar wind supratherm…

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Correlations are studied between the power density of transverse waves having frequencies between $0.01$ and $1$ normalized to the proton gyrofrequency in the plasma frame and the ratio of the perpendicular and parallel temperature of the…

Solar and Stellar Astrophysics · Physics 2010-08-04 Sofiane Bourouaine , Eckart Marsch , Fritz M. Neubauer

Hybrid-kinetic numerical simulations of firehose and mirror instabilities in a collisionless plasma are performed in which pressure anisotropy is driven as the magnetic field is changed by a persistent linear shear $S$. For a decreasing…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Matthew W. Kunz , Alexander A. Schekochihin , James M. Stone

Interplanetary shocks are one of the proposed sources of suprathermal ion populations (i.e., ions with energies of a few times the solar wind energy). Here, we present results from a series of three-dimensional hybrid simulations of…

Space Physics · Physics 2020-07-15 Matthew A. Young , Bernard J. Vasquez , Harald Kucharek , Noé Lugaz

We survey the electron heat flux observed by the Parker Solar Probe (PSP) in the near-Sun environment at heliocentric distances of 0.125-0.25 AU. We utilized measurements from the Solar Wind Electrons Alphas and Protons and FIELDS…

We propose a kinetic model describing the formation of the strahl and halo electron populations in the solar wind. We demonstrate that the suprathermal electrons propagating from the sun along the Parker-spiral magnetic field lines are…

Space Physics · Physics 2019-01-09 Konstantinos Horaites , Stanislav Boldyrev , Mikhail V. Medvedev

In this work, we derive a dispersion equation that describes the excitation of the oblique (or Alfv\'en) firehose instability in a plasma that contains both electron and ion species modelled by bi-kappa velocity distribution functions. The…

Plasma Physics · Physics 2018-11-19 Anelise Ramires Meneses , Rudi Gaelzer , Luiz Fernando Ziebell

Estimation of the energy cascade rate in the inertial range of solar wind turbulence has been done so far mostly within the incompressible magnetohydrodynamics (MHD) theory. Here, we go beyond that approximation to include plasma…

Solar and Stellar Astrophysics · Physics 2017-03-29 L. Z. Hadid , F. Sahraoui , S. Galtier

A well-known property of solar wind plasma turbulence is the observed anisotropy of the autocorrelations, or equivalently the spectra, of velocity and magnetic field fluctuations. Here we explore the related but apparently not well-studied…

Minor ions in the solar corona are heated to extreme temperatures, far in excess of those of the electrons and protons that comprise the bulk of the plasma. These highly non-thermal distributions make minor ions sensitive probes of the…

Solar and Stellar Astrophysics · Physics 2024-11-21 Michael F. Zhang , Matthew W. Kunz , Jonathan Squire , Kristopher G. Klein

Evidence for inhomogeneous heating in the interplanetary plasma near current sheets dynamically generated by magnetohydrodynamic (MHD) turbulence is obtained using measurements from the ACE spacecraft. These coherent structures only…

Space Physics · Physics 2013-12-04 K. T. Osman , W. H. Matthaeus , M. Wan , A. F. Rappazzo

Characterizing the plasma state in the near-Sun environment is essential to constrain the mechanisms that heat and accelerate the solar wind. In this study, we use Parker Solar Probe (PSP) observations from Encounters 1 through 24 to…

Ion anisotropies can affect a host of processes within the magnetosphere, from modifying the growth rate of various instabilities to the energization and mass transport within the magnetosphere. Global multi-fluid simulations using a full…

Earth and Planetary Astrophysics · Physics 2016-05-05 Robert Winglee , Erika Harnett

We derive a set of self-consistent marginally stable states for a system of ion-cyclotron waves propagating parallel to the large-scale magnetic field through a homogeneous proton-electron plasma. The proton distributions and the wave…

Space Physics · Physics 2015-06-16 Philip A. Isenberg , Bennett A. Maruca , Justin C. Kasper

The impact of superthermal electrons on dispersion properties of isotropic plasmas and on the modulational instability of a monochromatic Langmuir wave is studied for the case when the power-law tail of the electron distribution function…

Plasma Physics · Physics 2015-06-12 I. V. Timofeev

We use 2D particle-in-cell (PIC) simulations to study the effect of the saturated whistler instability on the viscous heating and nonthermal acceleration of electrons in a shearing, collisionless plasma with a growing magnetic field,…

High Energy Astrophysical Phenomena · Physics 2017-12-06 Mario Riquelme , Alvaro Osorio , Eliot Quataert

The fast solar wind's high speeds and nonthermal features require that significant heating occurs well above the Sun's surface. Two leading theories seem incompatible: low-frequency "Alfv\'enic" turbulence, which transports energy outwards…

Solar and Stellar Astrophysics · Physics 2022-02-25 Jonathan Squire , Romain Meyrand , Matthew W. Kunz , Lev Arzamasskiy , Alexander A. Schekochihin , Eliot Quataert

The high-speed solar wind is typically the simplest and least stochastic type of large-scale plasma flow in the heliosphere. For much of the solar cycle, it is connected magnetically to large polar coronal holes on the Sun's surface.…

Solar and Stellar Astrophysics · Physics 2020-12-22 Steven R. Cranmer

Energy conversion via reconnecting current sheets is common in space and astrophysical plasmas. Frequently, current sheets disrupt at multiple reconnection sites, leading to the formation of plasmoid structures between sites, which might…

In situ observations of the solar wind frequently show the temperature of $\alpha$-particles (fully ionized helium), $T_\alpha$, to significantly differ from that of protons (ionized hydrogen), $T_p$. Many heating processes in the plasma…

The electrostatic instabilities driven by the gradients of the density, temperature and magnetic field, are discussed in their application to solar magnetic structures. Strongly growing modes are found for some typical plasma parameters.…

Solar and Stellar Astrophysics · Physics 2015-05-14 J. Vranjes , S. Poedts