Zobrazeno 1 - 10
of 424
pro vyhledávání: '"E, Engelbrecht"'
Publikováno v:
The Astrophysical Journal, Vol 977, Iss 2, p 174 (2024)
The pitch-angle diffusion coefficient (PADC) quantifies the effect of pitch-angle scattering on charged particles propagating through turbulent magnetic fields and is a key ingredient in understanding the diffusion of these particles along the backgr
Externí odkaz:
https://doaj.org/article/b6567f4cc08546e7a267667c8fa080ee
Autor:
N. E. Engelbrecht
Publikováno v:
The Astrophysical Journal, Vol 975, Iss 2, p 227 (2024)
Modeling the transport of low-energy (1−10 MeV) cosmic-ray electrons can lead to valuable insights as to the behavior of the heliospheric magnetic field (HMF), due to the fact that the mean free path (MFP) of these particles parallel to the HMF is
Externí odkaz:
https://doaj.org/article/7f011c3f5cec4320a041e0595b8791f5
Publikováno v:
The Astrophysical Journal, Vol 975, Iss 1, p 134 (2024)
The natural variation in plasma parameters observed at 1 au can lead to a variation in transport parameters, such as diffusion and drift coefficients, for energetic charged particles of solar and galactic origin. Given the importance of these paramet
Externí odkaz:
https://doaj.org/article/8c43732760804fe3bda7307863767acd
Autor:
J. T. Lang, R. D. Strauss, N. E. Engelbrecht, J. P. van den Berg, N. Dresing, D. Ruffolo, R. Bandyopadhyay
Publikováno v:
The Astrophysical Journal, Vol 971, Iss 1, p 105 (2024)
In this work, more than a dozen solar energetic particle (SEP) events are identified where the source region is magnetically well connected to at least one spacecraft at 1 au. The observed intensity–time profiles, for all available proton and elect
Externí odkaz:
https://doaj.org/article/e9905e98fe7d4b5db8e3558ea40cdd67
Publikováno v:
The Astrophysical Journal, Vol 970, Iss 2, p 144 (2024)
Drifts due to the gradients in, and curvatures of, the heliospheric magnetic field (HMF) play a significant role in the transport of galactic cosmic rays (GCRs) in the heliosphere. Although this has been well studied for the Parker HMF, the influence
Externí odkaz:
https://doaj.org/article/e0635e8a44f04958b38ae4d4618a3fcf
Autor:
P. L. Els, N. E. Engelbrecht
Publikováno v:
The Astrophysical Journal, Vol 969, Iss 1, p 51 (2024)
Numerical simulations of test particle transport in the presence of synthetic turbulence with known properties still provide the most reliable estimations of the diffusion coefficients of charged particles in turbulent space plasmas available. The de
Externí odkaz:
https://doaj.org/article/2e7b17fd8c2d4f118069902156e0575c
Publikováno v:
The Astrophysical Journal, Vol 966, Iss 1, p 142 (2024)
The polytropic index is a fundamental physical parameter related to the thermodynamic processes present in space and astrophysical plasmas. This paper investigates the theoretical relationship between the polytropic index and the temperature anisotro
Externí odkaz:
https://doaj.org/article/b3d6244ec61945a788c73758413f6f1b
Publikováno v:
The Astrophysical Journal, Vol 962, Iss 2, p 186 (2024)
We present a stochastic field line mapping model where the interplanetary magnetic field lines are described by a density distribution function satisfying a Fokker–Planck equation that is solved numerically. Due to the spiral geometry of the nomina
Externí odkaz:
https://doaj.org/article/d3645040b39345e2b590c4c581145b2d
Autor:
Devojyoti Kansabanik, Surajit Mondal, Divya Oberoi, James O. Chibueze, N. E. Engelbrecht, R. D. Strauss, E. P. Kontar, G. J. J. Botha, P. J. Steyn, Amoré E. Nel
Publikováno v:
The Astrophysical Journal, Vol 961, Iss 1, p 96 (2024)
Solar radio emissions provide several unique diagnostics to estimate different physical parameters of the solar corona, which are otherwise simply inaccessible. However, imaging the highly dynamic solar coronal emissions spanning a large range of ang
Externí odkaz:
https://doaj.org/article/5b923b5b7fc94e46a8a7d5f8defc4d6a
Autor:
R. D. Strauss, N. Dresing, N. E. Engelbrecht, J. G. Mitchell, P. Kühl, S. Jensen, S. Fleth, B. Sánchez-Cano, A. Posner, J. S Rankin, C. O. Lee, J. P. van den Berg, S. E. S. Ferreira, B. Heber
Publikováno v:
The Astrophysical Journal, Vol 961, Iss 1, p 57 (2024)
In this paper we explore the idea of using multi-spacecraft observations of Jovian electrons to measure the 3D distribution of these particles in the inner heliosphere. We present simulations of Jovian electron intensities along selected spacecraft t
Externí odkaz:
https://doaj.org/article/903faa6e243d48b5aa38d1925092e7f2