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Related papers: Collisionless Isotropization of the Solar-Wind Pro…

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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

It is well-recognized that the presence of magnetic fields will lead to anisotropic energy cascade and dissipation of astrophysical turbulence. With the diffusion approximation and linear dissipation rates, we study the cascade and damping…

Solar and Stellar Astrophysics · Physics 2009-03-31 Yanwei Jiang , Siming Liu , Vahé Petrosian

Among the fundamental and most challenging problems of laboratory, space, and astrophysical plasma physics is to understand the relaxation processes of nearly collisionless plasmas toward quasi-stationary states; and the resultant states of…

Space Physics · Physics 2022-01-12 C. M. Espinoza , P. S. Moya , M. Stepanova , J. A. Valdivia , R. E. Navarro

Protons (ionized hydrogen) in the solar wind frequently exhibit distinct temperatures ($T_{\perp p}$ and $T_{\parallel p}$) perpendicular and parallel to the plasma's background magnetic-field. Numerous prior studies of the interplanetary…

Weakly collisional plasmas are subject to nonlinear relaxation processes, which can operate at rates much faster than the particle collision frequencies. This causes the plasma to respond like a magnetised fluid despite having long particle…

Space Physics · Physics 2022-10-12 J. T. Coburn , C. H. K. Chen , J. Squire

We study correlations of the temperature ratio (which is an indicator for perpendicular ion heating) and the differential flow of the alpha particles with the power of transverse fluctuations that have wave numbers between 0.01 and 0.1…

Solar and Stellar Astrophysics · Physics 2011-11-14 S. Bourouaine , E. Marsch , F. M. Neubauer

We investigate the role of kinetic instabilities driven by a proton anisotropy on the onset of magnetic reconnection by means of 2-D hybrid simulations. The collisionless tearing of a current sheet is studied in the presence of a proton…

Space Physics · Physics 2015-06-12 Lorenzo Matteini , Simone Landi , Marco Velli , William H. Matthaeus

Observations from Parker Solar Probe's first five orbits are used to investigate the helioradial evolution of probability density functions (PDFs) of fluctuations of magnetic field components, between \(\sim 28\) - 200 \(\rs\).…

Solar and Stellar Astrophysics · Physics 2022-11-09 Rohit Chhiber

Kinetic plasma processes have been investigated in the framework of solar wind turbulence, employing Hybrid Vlasov-Maxwell (HVM) simulations. The dependency of proton temperature anisotropy T_{\perp}/T_{\parallel} on the parallel plasma…

Solar wind magnetic fluctuations exhibit anisotropy due to the presence of a mean magnetic field in the form of the Parker spiral. Close to the Sun, direct measurements were not available until the recently launched Parker Solar Probe (PSP)…

Solar and Stellar Astrophysics · Physics 2022-01-05 Riddhi Bandyopadhyay , David J. McComas

We obtain scatter broadened images of the Crab Nebula at 80 MHz as it transits through the inner solar wind in June 2016 and 2017. These images are anisotropic, with the major axis oriented perpendicular to the radially outward coronal…

Solar and Stellar Astrophysics · Physics 2017-12-13 K. Sasikumar Raja , Prasad Subramanian , R. Ramesh , Angelos Vourlidas , Madhusudan Ingale

The relationship between a decaying strong turbulence and kinetic instabilities in a slowly expanding plasma is investigated using two-dimensional (2-D) hybrid expanding box simulations. We impose an initial ambient magnetic field…

A connection between kinetic processes and intermittent turbulence is observed in the solar wind plasma using measurements from the Wind spacecraft at 1 AU. In particular, kinetic effects such as temperature anisotropy and plasma heating…

Space Physics · Physics 2013-12-04 K. T. Osman , W. H. Matthaeus , B. Hnat , S. C. Chapman

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…

We present an analysis of the components of solar wind proton temperature perpendicular and parallel to the local magnetic field as a function of proximity to plasma instability thresholds. We find that $T_{\perp p}$ is enhanced near the…

Solar and Stellar Astrophysics · Physics 2009-11-17 J. C. Kasper , B. A. Maruca , S. D. Bale

We investigate the transition of the solar wind turbulent cascade from MHD to sub-ion range by means of a detail comparison between in situ observations and hybrid numerical simulations. In particular we focus on the properties of the…

Space Physics · Physics 2020-09-01 L. Matteini , L. Franci , O. Alexandrova , C. Lacombe , S. Landi , P. Hellinger , E. Papini , A. Verdini

We use a large, statistical set of measurements from the Wind spacecraft at 1 AU, and supporting synthetic spacecraft data based on kinetic plasma theory, to show that the compressible component of inertial range solar wind turbulence is…

Solar and Stellar Astrophysics · Physics 2015-05-28 G. G. Howes , S. D. Bale , K. G. Klein , C. H. K. Chen , C. S. Salem , J. M. TenBarge

Previous studies have shown that the observed temperature anisotropies of protons and alpha particles in the solar wind are constrained by theoretical thresholds for pressure-anisotropy-driven instabilities such as the…

Solar and Stellar Astrophysics · Physics 2015-06-17 Sofiane Bourouaine , Daniel Verscharen , Benjamin D. G. Chandran , Bennett A. Maruca , Justin C. Kasper

Measurements and simulations of inertial compressive turbulence in the solar wind are characterized by anti-correlated magnetic fluctuations parallel to the mean field and density structures. This signature has been interpreted as…

Space Physics · Physics 2018-03-14 Trevor A. Bowen , Samuel Badman , Petr Hellinger , Stuart D. Bale

A semi-empirical, axisymmetric model of the solar minimum corona is developed by solving the equations for conservation of mass and momentum with prescribed anisotropic temperature distributions. In the high-latitude regions, the proton…

Astrophysics · Physics 2009-11-10 Alberto M. Vasquez , Adriaan A. van Ballegooijen , John C. Raymond