Profile of a low-Mach-number shock in two-fluid plasma theory

Gedalin, M.; Kushinsky, Yam; Balikhin, M. A.

doi:10.5194/angeo-33-1011-2015

Cited by 3 publications

(3 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More importantly, we demonstrate that the ramp and precursors display a quasi-perpendicular geometry. This finding is in line with theoretical predictions (Gedalin 1998;Gedalin et al 2015), which suggest that a quasi-parallel shock becomes oblique, even quasi-perpendicular, due to the increase in transversal magnetic field amplitude in the ramp-overshoot region. However, prior to our study, observational support for this was limited (Balikhin et al 2023).…”

Section: Structure Of the Quasi-parallel Shock Transitionsupporting

confidence: 92%

Acceleration of Electrons and Ions by an “Almost” Astrophysical Shock in the Heliosphere

Jebaraj,

Agapitov,

Krasnoselskikh

et al. 2024

ApJL

View full text Add to dashboard Cite

Collisionless shock waves, ubiquitous in the Universe, are crucial for particle acceleration in various astrophysical systems. Currently, the heliosphere is the only natural environment available for their in situ study. In this work, we showcase the collective acceleration of electrons and ions by one of the fastest in situ shocks ever recorded, observed by the pioneering Parker Solar Probe at only 34.5 million km from the Sun. Our analysis of this unprecedented, near-parallel shock shows electron acceleration up to 6 MeV amidst intense multiscale electromagnetic wave emissions. We also present evidence of a variable shock structure capable of injecting and accelerating ions from the solar wind to high energies through a self-consistent process. The exceptional capability of the probe’s instruments to measure electromagnetic fields in a shock traveling at 1% the speed of light has enabled us, for the first time, to confirm that the structure of a strong heliospheric shock aligns with theoretical models of strong shocks observed in astrophysical environments. This alignment offers viable avenues for understanding astrophysical shock processes and the self-consistent acceleration of charged particles.

show abstract

Section: Structure Of the Quasi-parallel Shock Transitionsupporting

confidence: 92%

Acceleration of Electrons and Ions by an “Almost” Astrophysical Shock in the Heliosphere

Jebaraj,

Agapitov,

Krasnoselskikh

et al. 2024

ApJL

View full text Add to dashboard Cite

show abstract

“…Low Mach number shocks in the heliosphere are also usually approximately planar and stationary. Based on these conditions and following Gedalin et al (2015), two-fluid plasma theory should be an appropriate analytical approach to study the shock front structure. Within this approach, we consider a one-dimensional stationary plasma where all variables depend only on the coordinate x along the shock normal.…”

Section: The Upstream Magnetic Field From the Two-fluid Plasma Modelmentioning

confidence: 99%

Structure of a Quasi-parallel Shock Front

Balikhin,

Gedalin,

Walker

et al. 2023

ApJ

View full text Add to dashboard Cite

The aim of this study is to compare observations of the magnetic field structure of observed quasi-parallel collisionless shock fronts with the results obtained analytically. A two-fluid analytic model of the shock front structure was derived under the assumptions that the shock is stationary and planar. The ion and electron kinetic pressures were assumed to be scalar, and polytropic state equations were used. The results of this analytical approach show that the shock magnetic field has an oscillatory structure. Venus Express (VEX) observations of the Venusian bow shock have been used to validate these theoretical findings. The Venusian bow shock and corresponding foreshock are significantly smaller than those of Earth. Thus, observations of the underlying structure of the quasi-parallel shock at Venus are not masked by the presence of high-amplitude waves and nonlinear structures originating in the foreshock. It is shown that the structure of the shock front, as observed by VEX, has a very strong similarity to the structure obtained analytically.

show abstract

“…Yet, upstream of the ramp the two-fluid approach is still a good approximation. It was shown that even if restricting for the upstream region only, stationary solutions with decaying oscillations exist only if dissipation is invoked (Gedalin, Kushinsky & Balikhin 2015 b ). This brings us to the conclusion that even low-Mach shocks may be intrinsically non-stationary and generate upstream propagating whistler wave trains.…”

Section: Introductionmentioning

confidence: 99%

Whistler precursor and intrinsic variability of quasi-perpendicular shocks

Granit

Gedalin

2018

J. Plasma Phys.

View full text Add to dashboard Cite

The structure of whistler precursor in a quasi-perpendicular shock is studied within two-fluid approach in one-dimensional case. The complete set of equations is reduced to the KdV equation, if no dissipation is included. With a phenomenological resistive dissipation the structure is described with the KdV-Burgers equation. The shock profile is intrinsically time dependent. For sufficiently strong dissipation, temporal evolution of a steepening profile results in generation of a stationary decaying whistler ahead of the shock front. With the decrease of the dissipation parameter whistler wavetrains begin to detach and propagate toward upstream and the ramp is weakly time dependent. In the weakly dissipative regime the shock front experiences reformation. †

show abstract

Profile of a low-Mach-number shock in two-fluid plasma theory

Cited by 3 publications

References 36 publications

Acceleration of Electrons and Ions by an “Almost” Astrophysical Shock in the Heliosphere

Acceleration of Electrons and Ions by an “Almost” Astrophysical Shock in the Heliosphere

Structure of a Quasi-parallel Shock Front

Whistler precursor and intrinsic variability of quasi-perpendicular shocks

Contact Info

Product

Resources

About