The radial and latitudinal dependence of the cosmic ray diffusion tensor in the heliosphere

1998 ◽  
Vol 103 (A2) ◽  
pp. 2085-2097 ◽  
Author(s):  
G. P. Zank ◽  
W. H. Matthaeus ◽  
J. W. Bieber ◽  
H. Moraal
Keyword(s):  
Diffusion Tensor ◽  
Cosmic Ray ◽  
Latitudinal Dependence ◽  
Ray Diffusion

The Cosmic‐Ray Diffusion Tensor in Nonaxisymmetric Turbulence

2008 ◽  
Vol 677 (1) ◽  
pp. 671-675 ◽  
Author(s):  
B. Weinhorst ◽  
A. Shalchi ◽  
H. Fichtner
Keyword(s):  
Diffusion Tensor ◽  
Cosmic Ray ◽  
Ray Diffusion

scholarly journals Cosmic ray diffusion tensor throughout the heliosphere

2010 ◽  
Vol 115 (A3) ◽  
pp. n/a-n/a ◽  
Author(s):  
C. Pei ◽  
J. W. Bieber ◽  
B. Breech ◽  
R. A. Burger ◽  
J. Clem ◽  
...  
Keyword(s):  
Diffusion Tensor ◽  
Cosmic Ray ◽  
Ray Diffusion

scholarly journals CTA and cosmic-ray diffusion in molecular clouds

2012 ◽  
Author(s):  
G. Pedaletti ◽  
D. F. Torres ◽  
S. Gabici ◽  
E. de Oña Wilhelmi ◽  
D. Mazin ◽  
...  
Keyword(s):  
Molecular Clouds ◽  
Cosmic Ray ◽  
Ray Diffusion

scholarly journals X-ray Dips in AGN and Microquasars – Collapse Timescales of Inner Accretion Disc

2020 ◽  
Author(s):  
Mayur B Shende ◽  
Prashali Chauhan ◽  
Prasad Subramanian
Keyword(s):  
Collisionless Plasma ◽  
Cosmic Ray ◽  
Outer Radius ◽  
Accretion Disc ◽  
Accretion Discs ◽  
X Rays ◽  
Temporal Behaviour ◽  
X Ray ◽  
Ray Diffusion ◽  
3C 120

Abstract The temporal behaviour of X-rays from some AGN and microquasars is thought to arise from the rapid collapse of the hot, inner parts of their accretion discs. The collapse can occur over the radial infall timescale of the inner accretion disc. However, estimates of this timescale are hindered by a lack of knowledge of the operative viscosity in the collisionless plasma comprising the inner disc. We use published simulation results for cosmic ray diffusion through turbulent magnetic fields to arrive at a viscosity prescription appropriate to hot accretion discs. We construct simplified disc models using this viscosity prescription and estimate disc collapse timescales for 3C 120, 3C 111, and GRS 1915+105. The Shakura-Sunyaev α parameter resulting from our model ranges from 0.02 to 0.08. Our inner disc collapse timescale estimates agree well with those of the observed X-ray dips. We find that the collapse timescale is most sensitive to the outer radius of the hot accretion disc.

scholarly journals Kinematic models of the interplanetary magnetic field

2019 ◽  
Vol 37 (3) ◽  
pp. 299-314 ◽  
Author(s):  
Christoph Lhotka ◽  
Yasuhito Narita
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Current Knowledge ◽  
Cosmic Ray ◽  
Charged Dust ◽  
Cosmic Ray Modulation ◽  
Latitudinal Dependence ◽  
Magnetic Field Model ◽  
Kinematic Models ◽  
Turbulence Effect

Abstract. Current knowledge on the description of the interplanetary magnetic field is reviewed with an emphasis on the kinematic approach as well as the analytic expression. Starting with the Parker spiral field approach, further effects are incorporated into this fundamental magnetic field model, including the latitudinal dependence, the poleward component, the solar cycle dependence, and the polarity and tilt angle of the solar magnetic axis. Further extensions are discussed in view of the magnetohydrodynamic treatment, the turbulence effect, the pickup ions, and the stellar wind models. The models of the interplanetary magnetic field serve as a useful tool for theoretical studies, in particular on the problems of plasma turbulence evolution, charged dust motions, and cosmic ray modulation in the heliosphere.

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