scholarly journals Cosmic rays propagation along solar magnetic field lines: a fractional approach

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Vladimir Uchaikin ◽  
Renat Sibatov ◽  
Alexander Byzykchi
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Solar Magnetic Field ◽  
Field Lines

Time Variation of the Global Solar Magnetic Field Inferred from the Sun’s Shadow as Seen in 10 TeV Cosmic Rays

1998 ◽  
pp. 465-466
Author(s):  
L. K. Ding ◽  
◽  
M. Nishizawa ◽  
T. Sasaki ◽  
Y. H. Tan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Time Variation ◽  
Solar Magnetic Field

scholarly journals Dynamical Galactic Halos

1993 ◽  
Vol 157 ◽  
pp. 415-419
Author(s):  
D. Breitschwerdt ◽  
H.J. Völk ◽  
V. Ptuskin ◽  
V. Zirakashvili
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
The Other ◽  
Galactic Rotation ◽  
Galactic Halos ◽  
Magnetic Forces ◽  
Dynamical Coupling ◽  
Field Lines ◽  
The Magnetic Field ◽  
Open Magnetic Field

It is argued that the description of the magnetic field in halos of galaxies should take into account its dynamical coupling to the other major components of the interstellar medium, namely thermal plasma and cosmic rays (CR's). It is then inevitable to have some loss of gas and CR's (galactic wind) provided that there exist some “open” magnetic field lines, facilitating their escape, and a sufficient level of self-generated waves which couple the particles to the gas. We discuss qualitatively the topology of the magnetic field in the halo and show how galactic rotation and magnetic forces can be included in such an outflow picture.

scholarly journals The Ulysses fast latitude scans: COSPIN/KET results

2003 ◽  
Vol 21 (6) ◽  
pp. 1275-1288 ◽  
Author(s):  
B. Heber ◽  
G. Sarri ◽  
G. Wibberenz ◽  
C. Paizis ◽  
P. Ferrando ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Solar Magnetic Field ◽  
Solar Maximum ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Solar Particle Events ◽  
Interplanetary Magnetic Fields ◽  
Solar Particle ◽  
Interplanetary Physics

Abstract. Ulysses, launched in October 1990, began its second out-of-ecliptic orbit in December 1997, and its second fast latitude scan in September 2000. In contrast to the first fast latitude scan in 1994/1995, during the second fast latitude scan solar activity was close to maximum. The solar magnetic field reversed its polarity around July 2000. While the first latitude scan mainly gave a snapshot of the spatial distribution of galactic cosmic rays, the second one is dominated by temporal variations. Solar particle increases are observed at all heliographic latitudes, including events that produce >250 MeV protons and 50 MeV electrons. Using observations from the University of Chicago’s instrument on board IMP8 at Earth, we find that most solar particle events are observed at both high and low latitudes, indicating either acceleration of these particles over a broad latitude range or an efficient latitudinal transport. The latter is supported by "quiet time" variations in the MeV electron background, if interpreted as Jovian electrons. No latitudinal gradient was found for >106 MeV galactic cosmic ray protons, during the solar maximum fast latitude scan. The electron to proton ratio remains constant and has practically the same value as in the previous solar maximum. Both results indicate that drift is of minor importance. It was expected that, with the reversal of the solar magnetic field and in the declining phase of the solar cycle, this ratio should increase. This was, however, not observed, probably because the transition to the new magnetic cycle was not completely terminated within the heliosphere, as indicated by the Ulysses magnetic field and solar wind measurements. We argue that the new A<0-solar magnetic modulation epoch will establish itself once both polar coronal holes have developed.Key words. Interplanetary physics (cosmic rays; energetic particles; interplanetary magnetic fields)

scholarly journals Cosmic-ray propagation around the Sun: investigating the influence of the solar magnetic field on the cosmic-ray Sun shadow

2020 ◽  
Vol 633 ◽  
pp. A83
Author(s):  
J. Becker Tjus ◽  
P. Desiati ◽  
N. Döpper ◽  
H. Fichtner ◽  
J. Kleimann ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Activity ◽  
Solar Cycle ◽  
Cosmic Rays ◽  
Solar Magnetic Field ◽  
Cosmic Ray ◽  
High Energy ◽  
High Solar Activity ◽  
The Sun ◽  
Theoretical Understanding

The cosmic-ray Sun shadow, which is caused by high-energy charged cosmic rays being blocked and deflected by the Sun and its magnetic field, has been observed by various experiments, such as Argo-YBJ, Tibet, HAWC, and IceCube. Most notably, the shadow’s size and depth was recently shown to correlate with the 11-year solar cycle. The interpretation of such measurements, which help to bridge the gap between solar physics and high-energy particle astrophysics, requires a solid theoretical understanding of cosmic-ray propagation in the coronal magnetic field. It is the aim of this paper to establish theoretical predictions for the cosmic-ray Sun shadow in order to identify observables that can be used to study this link in more detail. To determine the cosmic-ray Sun shadow, we numerically compute trajectories of charged cosmic rays in the energy range of 5−316 TeV for five different mass numbers. We present and analyze the resulting shadow images for protons and iron, as well as for typically measured cosmic-ray compositions. We confirm the observationally established correlation between the magnitude of the shadowing effect and both the mean sunspot number and the polarity of the magnetic field during the solar cycle. We also show that during low solar activity, the Sun’s shadow behaves similarly to that of a dipole, for which we find a non-monotonous dependence on energy. In particular, the shadow can become significantly more pronounced than the geometrical disk expected for a totally unmagnetized Sun. For times of high solar activity, we instead predict the shadow to depend monotonously on energy and to be generally weaker than the geometrical shadow for all tested energies. These effects should become visible in energy-resolved measurements of the Sun shadow, and may in the future become an independent measure for the level of disorder in the solar magnetic field.

On the influence of solar activity and the solar magnetic field on the 27-day variation of galactic cosmic rays

2003 ◽  
Vol 32 (4) ◽  
pp. 621-626 ◽  
Author(s):  
E.S. Vernova ◽  
M.I. Tyasto ◽  
D.G. Baranov ◽  
M.V. Alania ◽  
A. Gil
Keyword(s):  
Magnetic Field ◽  
Solar Activity ◽  
Cosmic Rays ◽  
Solar Magnetic Field ◽  
Galactic Cosmic Rays

scholarly journals Cosmic Rays and the Parker Instability

1985 ◽  
Vol 107 ◽  
pp. 361-363
Author(s):  
A.H. Nelson
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Interstellar Medium ◽  
Galactic Halo ◽  
Cosmic Ray ◽  
Interstellar Gas ◽  
Horizontal Magnetic Field ◽  
Magnetic Buoyancy ◽  
Field Lines ◽  
Gas Layer

Parker (1966, 1969, 1979) has shown that the magnetic buoyancy of a uniform horizontal magnetic field will destabilize the Galactic gas layer. Perturbations of the form shown in Fig. 1 will grow in time with the magnetic loops ballooning up into the Galactic halo, and the interstellar gas draining down the field lines to collect in the mid-plane. Parker also showed that if the dynamical effect of the cosmic ray component of the interstellar medium is included, using an isotropic cosmic ray pressure, then the instability is enhanced.

scholarly journals Influence of the Solar Magnetic Field Upon Cosmic Rays

1938 ◽  
Vol 53 (11) ◽  
pp. 862-866 ◽  
Author(s):  
Paul S. Epstein
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Solar Magnetic Field

Solar magnetic field and dynamic phenomena in cosmic rays

2002 ◽  
Vol 29 (3) ◽  
pp. 331-336 ◽  
Author(s):  
M.B. Krainev ◽  
G.A. Bazilevskaya ◽  
V.S. Makhmutov
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Solar Magnetic Field ◽  
Dynamic Phenomena

scholarly journals Deflection of Cosmic Rays in the Solar Magnetic Field

1950 ◽  
Vol 2 (3) ◽  
pp. 77-80 ◽  
Author(s):  
Yataro SEKIDO ◽  
Teiichiro YAGI
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Solar Magnetic Field
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