aligned magnetic field
meydân-e meqnâtisi-ye âxatidé
Fr.: champ magnétique aligné
A magnetic field whose lines of force are oriented along a particular direction or by a particular manner (axially, vertically; randomly, properly, etc.)
azimuthal magnetic field
meydân-e meqnâtisi-ye sugâni
Fr.: champ magnétiquue azimutal
In the → solar dynamo model, a magnetic field that points from east to west or vice-versa.
circular magnetic field
meydân-e meqnâtisi-ye dâyere-yi
Fr.: champ magnétique circulaire
Relative to or characterized by → diamagnetism.
dipolar magnetic field
meydân-e meqnâtisi-ye dipoli, ~ ~ diqotbi
Fr.: champ magnétique dipolaire
Of or pertaining to electromagnetism or electromagnetic fields.
Fr.: contrpartie électromagnétique
An → electromagnetic signal associated with the location on the sky and the time of a → gravitational wave event. The electromagnetic signal is predicted by models to be associated with the → merger of a → compact binary star system composed of two → neutron stars (NS) or a neutron star and a → black hole (BH). Accordingly, the gravitational waves are accompanied by a short-duration → gamma-ray burst (GRB) powered by the → accretion of material that remains in a → centrifugally supported → torus around the BH following the merger. NS-NS/BH-NS mergers are also predicted to be accompanied by a more isotropic counterpart, commonly known as a → kilonova. Kilonovae are day to week-long thermal, → supernova-like → transients, and are powered by the → radioactive decay of heavy, neutron-rich elements synthesized by the → r-process in the expanding merger ejecta (Li and Paczynski 1998). The first detection of an electromagnetic counterpart to gravitational waves belongs to → GW170817.
electromagnetic coupling constant
pâyâ-ye jafsari-ye barqâmeqnâti
Fr.: constante de couplage electromagnétique
Same as → fine-structure constant.
Fr.: champ électromagnétique
A region of space consisting of coupled electric and magnetic lines of force at each point, generated by time-varying currents and accelerated charges.
Fr.: force électromagnétique
The fundamental force that is associated with electric and magnetic fields. One of the four fundamental forces of nature, it is carried by photons.
Fr.: induction électromagnétique
The production of an → electromotive force in a circuit caused by a variation in the magnetic flux through the circuit. If this variation is produced by a change in the current flowing in the circuit itself, it is called → self-induction. If due to the variation in a current in some other circuit, it is called mutual induction. See also → Faraday's law of induction.
Fr.: potentiel électromagnétique
Fr.: rayonnement électromagnétique
Radiation propagating in the form of an advancing wave in electric and magnetic fields. It includes radio waves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
Fr.: signal électromagnétique
Information transmitted by means of a modulated current or an electromagnetic wave and received by telephone, radio, television, etc.
Fr.: spectre électromagnétique
The range of frequencies over which electromagnetic waves are propagated. → electromagnetic radiation.
Fr.: théorie électromagnétique
electromagnetic theory of light
negare-ye barqâmeqnâti-ye nur
Fr.: théorie électromagnétique de la lumière
The theory describing light as a wave phenomenon resulting from the combination of two electric and magnetic fields vibrating transversely and mutually at right angles. → electromagnetic radiation; → electromagnetic wave; → Maxwell's equations.
Fr.: onde électromagnétique
A wave produced by oscillation or acceleration of an electric charge. → electromagnetic radiation.
Relative to or characterized by → ferromagnetism.
force-free magnetic field
Fr.: champ magnétique sans force
The condition in a plasma when the → Lorentz force is zero, that is when the electric current flows along the magnetic field. Force-free magnetic fields are encountered in astrophysical plasmas with negligible gas pressure. The solar corona is the best available example of such fields in action in a plasma.