Search Publications

Compressive Coherent Structures at Ion Scales in the Slow Solar Wind
DOI: 10.3847/0004-637X/826/2/196 Bibcode: 2016ApJ...826..196P

Maksimovic, M.; Alexandrova, O.; Kasper, J. C. +5 more

We present a study of magnetic field fluctuations in a slow solar wind stream, close to ion scales, where an increase of the level of magnetic compressibility is observed. Here, the nature of these compressive fluctuations is found to be characterized by coherent structures. Although previous studies have shown that current sheets can be considere…

2016 The Astrophysical Journal
Cluster 95
The Complex Structure of Magnetic Field Discontinuities in the Turbulent Solar Wind
DOI: 10.3847/2041-8205/823/2/L39 Bibcode: 2016ApJ...823L..39G

Perri, S.; Veltri, P.; Yordanova, E. +2 more

Using high-resolution Cluster satellite observations and a multi-dimensional intermittency technique, we show that the magnetic discontinuities in the turbulent solar wind are connected through the spatial scales, going from proton down to electron scales. In some circumstances, their structure resembles the Harris equilibrium profile in plasmas. …

2016 The Astrophysical Journal
Cluster 78
Subproton-scale Cascades in Solar Wind Turbulence: Driven Hybrid-kinetic Simulations
DOI: 10.3847/2041-8205/822/1/L12 Bibcode: 2016ApJ...822L..12C

Rincon, F.; Califano, F.; Cerri, S. S. +2 more

A long-lasting debate in space plasma physics concerns the nature of subproton-scale fluctuations in solar wind (SW) turbulence. Over the past decade, a series of theoretical and observational studies were presented in favor of either kinetic Alfvén wave (KAW) or whistler turbulence. Here, we investigate numerically the nature of the subproton-sca…

2016 The Astrophysical Journal
Cluster 68
Suprathermal Electron Strahl Widths in the Presence of Narrow-band Whistler Waves in the Solar Wind
DOI: 10.3847/1538-4357/833/2/172 Bibcode: 2016ApJ...833..172K

Fazakerley, A. N.; Maksimovic, M.; Alexandrova, O. +2 more

We perform the first statistical study of the effects of the interaction of suprathermal electrons with narrow-band whistler mode waves in the solar wind (SW). We show that this interaction does occur and that it is associated with enhanced widths of the so-called strahl component. The latter is directed along the interplanetary magnetic field awa…

2016 The Astrophysical Journal
Cluster 44
The Dynamical Generation of Current Sheets in Astrophysical Plasma Turbulence
DOI: 10.3847/2041-8205/827/2/L28 Bibcode: 2016ApJ...827L..28H

Howes, Gregory G.

Turbulence profoundly affects particle transport and plasma heating in many astrophysical plasma environments, from galaxy clusters to the solar corona and solar wind to Earth's magnetosphere. Both fluid and kinetic simulations of plasma turbulence ubiquitously generate coherent structures, in the form of current sheets, at small scales, and the l…

2016 The Astrophysical Journal
Cluster 38
Reconnection Properties of Large-scale Current Sheets During Coronal Mass Ejection Eruptions
DOI: 10.3847/0004-637X/826/1/43 Bibcode: 2016ApJ...826...43L

Lynch, B. J.; Guidoni, S. E.; Edmondson, J. K. +1 more

We present a detailed analysis of the properties of magnetic reconnection at large-scale current sheets (CSs) in a high cadence version of the Lynch & Edmondson 2.5D MHD simulation of sympathetic magnetic breakout eruptions from a pseudostreamer source region. We examine the resistive tearing and break-up of the three main CSs into chains of X…

2016 The Astrophysical Journal
Cluster 37
Ion Dynamics at a Rippled Quasi-parallel Shock: 2D Hybrid Simulations
DOI: 10.3847/0004-637X/823/1/7 Bibcode: 2016ApJ...823....7H

Wang, Shui; Hao, Yufei; Lu, Quanming +1 more

In this paper, two-dimensional hybrid simulations are performed to investigate ion dynamics at a rippled quasi-parallel shock. The results show that the ripples around the shock front are inherent structures of a quasi-parallel shock, and the re-formation of the shock is not synchronous along the surface of the shock front. By following the trajec…

2016 The Astrophysical Journal
Cluster 33
Ion Acceleration at the Quasi-parallel Bow Shock: Decoding the Signature of Injection
DOI: 10.3847/0004-637X/820/1/21 Bibcode: 2016ApJ...820...21S

Burgess, D.; Sundberg, Torbjörn; Haynes, Christopher T. +1 more

Collisionless shocks are efficient particle accelerators. At Earth, ions with energies exceeding 100 keV are seen upstream of the bow shock when the magnetic geometry is quasi-parallel, and large-scale supernova remnant shocks can accelerate ions into cosmic-ray energies. This energization is attributed to diffusive shock acceleration however, for…

2016 The Astrophysical Journal
Cluster 29
The Effects of Kinetic Instabilities on Small-scale Turbulence in Earth’s Magnetosheath
DOI: 10.3847/0004-637X/829/1/54 Bibcode: 2016ApJ...829...54B

Vaivads, A.; Alexandrova, O.; Breuillard, H. +1 more

The Earth's magnetosheath is the region delimited by the bow shock and the magnetopause. It is characterized by highly turbulent fluctuations covering all scales from MHD down to kinetic scales. Turbulence is thought to play a fundamental role in key processes such as energy transport and dissipation in plasma. In addition to turbulence, different…

2016 The Astrophysical Journal
Cluster 27
Turbulence-generated Proton-scale Structures in the Terrestrial Magnetosheath
DOI: 10.3847/2041-8205/819/1/L15 Bibcode: 2016ApJ...819L..15V

Echim, Marius M.; Consolini, Giuseppe; Vörös, Zoltán +2 more

Recent results of numerical magnetohydrodynamic simulations suggest that in collisionless space plasmas, turbulence can spontaneously generate thin current sheets. These coherent structures can partially explain the intermittency and the non-homogenous distribution of localized plasma heating in turbulence. In this Letter, Cluster multi-point obse…

2016 The Astrophysical Journal
Cluster 23