Strahl (astronomy)
Encyclopedia
Strahl is the electron
component of the solar wind
that is the most closely aligned with the magnetic field
of the Sun
. These electrons are part of the high speed component of the solar wind and have sufficient velocity to escape from the electrostatic potential of the Sun. They carry the electron heat flux of the solar wind and always move away from the Sun along the magnetic field
lines. Strahl are distinguished from the 'core' and 'halo' populations of electrons, which form part of the low and high speed solar winds and are normally anisotropic with respect to the Sun's magnetic field.
Electrons precipitating into the polar regions of the Sun form the source of the strahl. When the magnetic lines of force are connected with the interplanetary magnetic field (IMF) in the appropriate direction, the strahl electrons are transported from the solar corona with energies of up to several hundred eV. When the Sun's magnetic field lines are not connected with the IMF, the strahl effect is blocked at that pole.
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
component of the solar wind
Solar wind
The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...
that is the most closely aligned with the magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
of the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
. These electrons are part of the high speed component of the solar wind and have sufficient velocity to escape from the electrostatic potential of the Sun. They carry the electron heat flux of the solar wind and always move away from the Sun along the magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
lines. Strahl are distinguished from the 'core' and 'halo' populations of electrons, which form part of the low and high speed solar winds and are normally anisotropic with respect to the Sun's magnetic field.
Electrons precipitating into the polar regions of the Sun form the source of the strahl. When the magnetic lines of force are connected with the interplanetary magnetic field (IMF) in the appropriate direction, the strahl electrons are transported from the solar corona with energies of up to several hundred eV. When the Sun's magnetic field lines are not connected with the IMF, the strahl effect is blocked at that pole.