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Found 12 entries in the Bibliography.
Showing entries from 1 through 12
| 2021 |
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The role of solar wind expansion in generating whistler waves is investigated using the EB-iPic3D code, which models solar wind expansion self-consistently within a fully kinetic semi-implicit approach. The simulation is initialized with an electron velocity distribution function modeled after observations of the Parker Solar Probe during its first perihelion at 0.166 au, consisting of a dense core and an antisunward strahl. This distribution function is initially stable with respect to kinetic instabilities. Expansion drive ... Micera, A.; Zhukov, A.~N.; opez, R.~A.; Boella, E.; Tenerani, A.; Velli, M.; Lapenta, G.; Innocenti, M.~E.; Published by: \apj Published on: sep YEAR: 2021 DOI: 10.3847/1538-4357/ac1067 Solar wind; Plasma astrophysics; Space plasmas; 1534; 1261; 1544; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics; Parker Data Used |
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Various forms of exact laws governing magnetohydrodynamic (MHD) turbulence have been derived either in the incompressibility limit, or for isothermal compressible flows. Here we propose a more general method that allows us to obtain such laws for any turbulent isentropic flow (i.e., constant entropy). We demonstrate that the known MHD exact laws (incompressible and isothermal) and the new (polytropic) one can be obtained as specific cases of the general law when the corresponding closure equation is stated. We also recover a ... Published by: \apj Published on: jul YEAR: 2021 DOI: 10.3847/1538-4357/ac0337 Solar wind; Solar Physics; Parker Data Used; Magnetohydrodynamics; Plasma astrophysics; Plasma physics; interplanetary turbulence; 1534; 1476; 1964; 1261; 2089; 830; Physics - Plasma Physics; Physics - Fluid Dynamics |
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First Observations of Anomalous Cosmic Rays in to 36 Solar Radii NASA s Parker Solar Probe mission continues to travel closer to the Sun than any prior human-made object, with an expected closest approach of <10 solar radii (<0.046 au) by 2024. On board, the Integrated Science Investigation of the Sun instrument suite makes unprecedented in situ measurements of energetic particles in the near-Sun environment. The current low level of solar activity offers a prime opportunity to measure cosmic rays closer to the Sun than ever before. We present the first observations of anomalous cosmic ra ... Rankin, J.; McComas, D.; Leske, R.; Christian, E.; Cohen, C.; Cummings, A.; Joyce, C.; Labrador, A.; Mewaldt, R.; Posner, A.; Schwadron, N.; Strauss, R.; Stone, E.; Wiedenbeck, M.; Published by: The Astrophysical Journal Published on: 05/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abec7e cosmic rays; Solar wind; Heliosphere; Solar energetic particles; Solar Physics; solar cycle; Quiet Sun; Particle astrophysics; interplanetary magnetic fields; Plasma astrophysics; Interplanetary particle acceleration; Pickup ions; 329; 1534; 711; 1491; 1476; 1487; 1322; 96; 824; 1261; 826; 1239; Parker Data Used |
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The random advection of passive additives in a turbulent fluid plays an important role in solar physics, astrophysics, and atmospheric sciences. We concern ourselves here with the case where the fluctuations are not statistically homogeneous in space, and, hence, where the transport coefficients vary with position. Using a numerical model in which the fluid turbulence is defined kinematically, we show that the evolution of the distribution of passive tracers in the fluid is not always governed by the ordinary diffusion equat ... Published by: The Astrophysical Journal Published on: 05/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abf0b2 Plasma astrophysics; Solar magnetic fields; hydrodynamics; Astrophysical fluid dynamics; Atmospheric science; 1261; 1503; 1963; 101; 116; Parker Data Used |
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Observations of plasma waves by the Fields Suite and of electrons by the Solar Wind Electrons Alphas and Protons Investigation on the Parker Solar Probe provide strong evidence for pitch angle scattering of strahl-energy electrons by narrowband whistler-mode waves at radial distances less than ∼0.3 au. We present two example intervals of a few hours each that include eight waveform captures with whistler-mode waves and 26 representative electron distributions that are examined in detail. Two were narrow, seventeen were cle ... Cattell, C.; Breneman, A.; Dombeck, J.; Short, B.; Wygant, J.; Halekas, J.; Case, Tony; Kasper, J.; Larson, D.; Stevens, Mike; Whittesley, P.; Bale, S.; de Wit, Dudok; Goodrich, K.; MacDowall, R.; Moncuquet, M.; Malaspina, D.; Pulupa, M.; Published by: The Astrophysical Journal Published on: 04/2021 YEAR: 2021 DOI: 10.3847/2041-8213/abefdd Parker Data Used; Solar wind; Space plasmas; Plasma astrophysics; Interplanetary physics; Interplanetary particle acceleration; 1534; 1544; 1261; 827; 826; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
| 2020 |
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Tearing Modes in Partially Ionized Astrophysical Plasma Pucci, Fulvia; Singh, Alkendra; Tenerani, Anna; Velli, Marco; Published by: \apjl Published on: 11/2020 YEAR: 2020 DOI: 10.3847/2041-8213/abc0e7 Parker Data Used; Solar magnetic reconnection; Plasma astrophysics; Space plasmas; Collision processes; 1504; 1261; 1544; 2065; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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We present results of a two-dimensional fully kinetic particle-in-cell simulation in order to shed light on the role of whistler waves in the scattering of strahl electrons and in the heat-flux regulation in the solar wind. We model the electron velocity distribution function as initially composed of core and strahl populations as typically encountered in the near-Sun solar wind as observed by Parker Solar Probe. We demonstrate that, as a consequence of the evolution of the electron velocity distribution function (VDF), two ... Micera, A.; Zhukov, A.; opez, R.; Innocenti, M.; Lazar, M.; Boella, E.; Lapenta, G.; Published by: The Astrophysical Journal Published on: 11/2020 YEAR: 2020 DOI: 10.3847/2041-8213/abc0e8 Parker Data Used; Solar wind; Space plasmas; Plasma astrophysics |
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Microinstabilities and waves excited at moderate-Mach-number perpendicular shocks in the near-Sun solar wind are investigated by full particle-in-cell simulations. By analyzing the dispersion relation of fluctuating field components directly issued from the shock simulation, we obtain key findings concerning wave excitations at the shock front: (1) at the leading edge of the foot, two types of electrostatic (ES) waves are observed. The relative drift of the reflected ions versus the electrons triggers an electron cyclotro ... Yang, Zhongwei; Liu, Ying; Matsukiyo, Shuichi; Lu, Quanming; Guo, Fan; Liu, Mingzhe; Xie, Huasheng; Gao, Xinliang; Guo, Jun; Published by: The Astrophysical Journal Published on: 09/2020 YEAR: 2020 DOI: 10.3847/2041-8213/abaf59 Interplanetary shocks; parker solar probe; Plasma astrophysics; Plasma physics; Solar Probe Plus; Space plasmas |
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The Electromagnetic Signature of Outward Propagating Ion-scale Waves First results from the Parker Solar Probe (PSP) mission have revealed ubiquitous coherent ion-scale waves in the inner heliosphere, which are signatures of kinetic wave-particle interactions and fluid instabilities. However, initial studies of the circularly polarized ion-scale waves observed by PSP have only thoroughly analyzed magnetic field signatures, precluding a determination of solar wind frame propagation direction and intrinsic wave polarization. A comprehensive determination of wave properties requires measureme ... Bowen, Trevor; Bale, Stuart; Bonnell, J.; Larson, Davin; Mallet, Alfred; McManus, Michael; Mozer, Forrest; Pulupa, Marc; Vasko, Ivan; Verniero, J.; Published by: The Astrophysical Journal Published on: 08/2020 YEAR: 2020 DOI: 10.3847/1538-4357/ab9f37 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Plasma astrophysics; Plasma physics; Solar Probe Plus; Solar wind; Space plasmas |
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Tearing Instability and Periodic Density Perturbations in the Slow Solar Wind In contrast with the fast solar wind, which originates in coronal holes, the source of the slow solar wind is still debated. Often intermittent and enriched with low first ionization potential elements\textemdashakin to what is observed in closed coronal loops\textemdashthe slow wind could form in bursty events nearby helmet streamers. Slow winds also exhibit density perturbations that have been shown to be periodic and could be associated with flux ropes ejected from the tip of helmet streamers, as shown recently by the ... Réville, Victor; Velli, Marco; Rouillard, Alexis; Lavraud, Benoit; Tenerani, Anna; Shi, Chen; Strugarek, Antoine; Published by: The Astrophysical Journal Published on: 05/2020 YEAR: 2020 DOI: 10.3847/2041-8213/ab911d Astrophysics - Solar and Stellar Astrophysics; Magnetohydrodynamics; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Plasma astrophysics; Slow solar wind; Solar magnetic reconnection; Solar Probe Plus; Solar wind |
| 2019 |
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Electron Energy Partition across Interplanetary Shocks. II. Statistics A statistical analysis of 15,210 electron velocity distribution function (VDF) fits, observed within \textpm2 hr of 52 interplanetary (IP) shocks by the Wind spacecraft near 1 au, is presented. This is the second in a three-part series on electron VDFs near IP shocks. The electron velocity moment statistics for the dense, low-energy core, tenuous, hot halo, and field-aligned beam/strahl are a statistically significant list of values illustrated with both histograms and tabular lists for reference and baselines in future w ... Wilson, Lynn; Chen, Li-Jen; Wang, Shan; Schwartz, Steven; Turner, Drew; Stevens, Michael; Kasper, Justin; Osmane, Adnane; Caprioli, Damiano; Bale, Stuart; Pulupa, Marc; Salem, Chadi; Goodrich, Katherine; Published by: The Astrophysical Journal Supplement Series Published on: 12/2019 YEAR: 2019 DOI: 10.3847/1538-4365/ab5445 Astrophysics - Solar and Stellar Astrophysics; Interplanetary particle acceleration; Interplanetary shocks; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Plasma astrophysics; Plasma physics; Solar coronal mass ejection shocks; Solar coronal mass ejections; Solar Probe Plus; Solar wind; Space plasmas |
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The large-scale features of the solar wind are examined in order to predict small-scale features of turbulence in unexplored regions of the heliosphere. The strategy is to examine how system size, or effective Reynolds number Re, varies, and then how this quantity influences observable statistical properties, including intermittency properties of solar wind turbulence. The expectation based on similar hydrodynamics scalings is that the kurtosis, of the small-scale magnetic field increments, will increase with increasing R ... Parashar, T.; Cuesta, M.; Matthaeus, W.; Published by: The Astrophysical Journal Published on: 10/2019 YEAR: 2019 DOI: 10.3847/2041-8213/ab4a82 Heliosphere; interplanetary turbulence; parker solar probe; Physics - Space Physics; Plasma astrophysics; Solar Probe Plus; Solar wind; Space plasmas |
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