Anomalous Resistivity on Auroral Field Lines and its Role in Auroral Particle Acceleration

1983 ◽  
pp. 437-452 ◽  
Author(s):  
A. A. Galeev
Keyword(s):  
Particle Acceleration ◽  
Anomalous Resistivity ◽  
Field Lines

scholarly journals Hybrid numerical simulations of pulsar magnetospheres

2019 ◽  
Vol 491 (4) ◽  
pp. 5579-5585 ◽  
Author(s):  
Ioannis Contopoulos ◽  
Jerome Pétri ◽  
Petros Stefanou
Keyword(s):  
Particle Acceleration ◽  
Current Sheet ◽  
Electric Current ◽  
Hybrid Approach ◽  
High Energy ◽  
Basic Premise ◽  
Analytic Approximations ◽  
Polar Caps ◽  
Electron Positron ◽  
Field Lines

ABSTRACT We continue our investigation of particle acceleration in the pulsar equatorial current sheet (ECS). Our basic premise has been that the charge carriers in the current sheet originate in the polar caps as electron–positron pairs, and are carried along field lines that enter the ECS beyond the magnetospheric Y-point. In this work, we investigate further the charge replenishment of the ECS. We discovered that the flow of pairs from the rims of the polar caps cannot supply both the electric charge and the electric current of the ECS. The ECS must contain an extra amount of positronic (or electronic depending on orientation) electric current that originates in the stellar surface and flows outwards along the separatrices. We develop an iterative hybrid approach that self-consistently combines ideal force-free electrodynamics in the bulk of the magnetosphere with particle acceleration along the ECS. We derive analytic approximations for the orbits of the particles, and obtain the structure of the pulsar magnetosphere for various values of the pair formation multiplicity parameter κ. For realistic values κ ≫ 1, the magnetosphere is practically indistinguishable from the ideal force-free one, and therefore, the calculation of the spectrum of high energy radiation must rely on analytic approximations for the distribution of the accelerating electric field in the ECS.

Plasma Potential Formation and Particle Acceleration Due to ECRH in Diverging Magnetic-Field Lines

1999 ◽  
Vol 35 (1T) ◽  
pp. 325-329 ◽  
Author(s):  
Rikizo Hatakeyama ◽  
Toshiro Kaneko ◽  
Noriyoshi Sato
Keyword(s):  
Magnetic Field ◽  
Particle Acceleration ◽  
Plasma Potential ◽  
Potential Formation ◽  
Field Lines

scholarly journals Particle Acceleration in the Process of Eruptive Opening and Reconnection of Magnetic Fields

1980 ◽  
Vol 91 ◽  
pp. 217-221 ◽  
Author(s):  
Z. Švestka ◽  
S. F. Martin ◽  
R. A. Kopp
Keyword(s):  
Magnetic Field ◽  
Shock Wave ◽  
Particle Acceleration ◽  
Magnetic Fields ◽  
Magnetic Loop ◽  
Coronal Loops ◽  
X Rays ◽  
Flare Loops ◽  
Field Lines ◽  
The Magnetic Field

In a series of papers on the flare of 29 July 1973 (Nolte et al., 1979; Martin, 1979; Švestka et al., 1979) it has been shown that Hα “post-flare” loops are the cooled aftermath of previously hot coronal loops which were visible in x-rays in the same position earlier in the flare. Kopp and Pneuman (1976) have proposed that these post-flare loops are formed by a process of successive magnetic field reconnections of previously distended magnetic field lines as illustrated in Figure 1. Each successive reconnection of the magnetic field yields a closed magnetic loop that forms above and concentric with previously formed loops. A shock wave created during each sudden reconnection travels down both legs of each loop and provides energy for ionizing chromospheric mass at the footpoints of the loop. Subsequent condensation of the ionized mass at the tops of the loops renders them visible as this mass falls to the chromosphere.

scholarly journals Jets of energetic particles generated by magnetic reconnection at a three-dimensional magnetic null

2006 ◽  
Vol 2 (14) ◽  
pp. 98-98
Author(s):  
Silvia Dalla ◽  
Philippa K. Browning
Keyword(s):  
Particle Acceleration ◽  
Magnetic Reconnection ◽  
Energetic Particle ◽  
Three Dimensional ◽  
Null Point ◽  
Numerical Code ◽  
Coronal Magnetic Fields ◽  
Field Lines ◽  
Magnetic Null ◽  
Magnetic Null Point

AbstractMagnetic reconnection is a candidate mechanism for particle acceleration in a variety of astrophysical contexts. It is now widely accepted that reconnection plays a key role in solar flares, and reconstructions of coronal magnetic fields indicate that three-dimensional (3D) magnetic null points can be present during flares. We investigate particle acceleration during spine reconnection at a 3D magnetic null point, using a test particle numerical code. We observe efficient particle acceleration and find that two energetic populations are produced: a trapped population of particles that remain in the vicinity of the null, and an escaping population, which leave the configuration in two symmetric jets along field lines near the spine. While the parameters used in our simulation aim to represent solar coronal plasma conditions of relevance for acceleration in flares, the fact that the 3D spine reconnection configuration naturally results in energetic particle jets may be of importance in other astrophysical situations. We also compare the results obtained for the spine reconnection regime with those for the other possible mode of 3D reconnection, fan reconnection. We find that in the latter case energetic particle jets are not produced, though acceleration is observed.

scholarly journals Jupiter Radio Bursts and Particle Acceleration

1994 ◽  
Vol 142 ◽  
pp. 541-546 ◽  
Author(s):  
Michael D. Desch
Keyword(s):  
Particle Acceleration ◽  
Plasma Wave ◽  
Close Association ◽  
High Energy ◽  
Radio Continuum ◽  
Radio Bursts ◽  
High Energy Electrons ◽  
Planets And Satellites ◽  
Wave Emission ◽  
Field Lines

AbstractParticle acceleration processes are important in understanding many of the Jovian radio and plasma wave emissions. However, except for the high-energy electrons that generate synchrotron emission following inward diffusion from the outer magnetosphere, acceleration processes in Jupiter’s magnetosphere and between Jupiter and Io are poorly understood. We discuss very recent observations from the Ulysses spacecraft of two new Jovian radio and plasma wave emissions in which particle acceleration processes are important and have been addressed directly by complementary investigations. First, radio bursts known as quasi-periodic bursts have been observed in close association with a population of highly energetic electrons. Second, a population of much lower energy (keV range) electrons on auroral field lines can be shown to be responsible for the first observation of a Jovian plasma wave emission known as auroral hiss.Subject headings: acceleration of particles — planets and satellites: individual (Jupiter) — radio continuum: solar system

scholarly journals Radio Astronomical Tools for the Study of Solar Energetic Particles I. Correlations and Diagnostics of Impulsive Acceleration and Particle Propagation

2021 ◽  
Vol 7 ◽  
Author(s):  
Karl-Ludwig Klein
Keyword(s):  
Particle Acceleration ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Relativistic Electrons ◽  
The Sun ◽  
Radio Bursts ◽  
Type Iii ◽  
Wide Range ◽  
Field Lines ◽  
Impulsive Processes

Solar energetic particles (SEPs) are sporadically ejected from the Sun during flares and coronal mass ejections. They are of major astrophysical interest, because the proximity of the Sun allows for detailed multi-messenger studies. They affect space weather due to interactions with electronics, with the Earth’s atmosphere, and with humans if they leave the protective shield of the magnetosphere of the Earth. Since early studies in the 1950s, starting with particle detectors on the ground, SEP events have been related to radio bursts. Two subjects are addressed in this chapter: attempts to establish quantitative correlations between SEPs and microwave bursts produced by gyro synchrotron radiation of mildly relativistic electrons, and the information derived from type III radio bursts on impulsive processes of particle acceleration and the coronal and interplanetary propagation. Type III radio bursts produced by electron beams on open magnetic field lines have a wide range of applications, including the identification of acceleration regions, the identification of confined particle acceleration with coronal signatures, but no SEPs, and the paths that the electrons, and energetic charged particles in general, take to travel from the low corona to the Heliosphere in case they escape. Simple scenarios of coronal particle acceleration are confirmed in relatively simple and short events. But the comparison with particle transport models shows that longer and delayed acceleration episodes exist especially in large SEP events. They will be discussed in a companion chapter.

scholarly journals Reconnection in a slow Coronal Mass Ejection

2008 ◽  
Vol 26 (10) ◽  
pp. 3067-3075 ◽  
Author(s):  
G. Poletto ◽  
A. Bemporad ◽  
F. Landini ◽  
M. Romoli
Keyword(s):  
Heliocentric Distance ◽  
Large Angle ◽  
Time Interval ◽  
Diffusion Region ◽  
Anomalous Resistivity ◽  
Reconnection Rate ◽  
Field Lines ◽  
Mass Ejection ◽  
Lower Limits ◽  
Spectrometric Coronagraph

Abstract. This paper aims at studying reconnection occurring in the aftermath of the 28 May 2004, CME, first imaged by the LASCO (Large Angle and Spectrometric Coronagraph) C2 at 11:06 UT. The CME was observed in White Light and UV radiation: images acquired by the LASCO C2 and C3 coronagraphs and spectra acquired by UVCS (Ultraviolet Coronagraph Spectrometer) allowed us to identify the level at which field lines, stretched outwards by the CME ejection, reconnect below the CME bubble. As the CME propagates outwards, reconnection occurs at increasingly higher levels. The process goes on at a low pace for several hours: here we give the profile of the reconnection rate vs. heliocentric distance over a time interval of ≈14 h after the CME onset, extending estimates of the reconnection rate to larger distances than previously inferred by other authors. The reconnection rate appears to decrease with time/altitude. We also calculate upper and lower limits to the density in the diffusion region between 4 and 7 R⊙ and conclude by comparing estimates of the classical and anomalous resistivity in the diffusion region with the value inferred from the data. The latter turns out to be ≥5 order of magnitudes larger than predicted by classical or anomalous theories, pointing to the need of identifying the process responsible for the observed value.

Anomalous resistivity on auroral field lines

1981 ◽  
Vol 8 (12) ◽  
pp. 1257-1260 ◽  
Author(s):  
H. L. Rowland ◽  
P. J. Palmadesso ◽  
K. Papadopoulos
Keyword(s):  
Anomalous Resistivity ◽  
Field Lines
Sign in / Sign up

Export Citation Format

Share Document