Of or pertaining to → astrophysics.
Fr.: jet astrophysique
A very fast moving, → collimated beam of → ionized gas at high temperatures associated with most classes of compact objects that spin and/or accrete matter from their surroundings, such as → protostars, → X-ray binary systems, and, at a larger scale, with → active galactic nuclei, → gamma-ray bursts, and → quasars. In general, jet sources host → accretion disks and are associated with → magnetic fields. Astrophysical jets, despite their different physical scales and power, are morphologically very similar, suggesting a common physical origin. For example, in one extreme, → active galactic nuclei jets have typical sizes ≥ 106 pc, velocities near that of light c, and parent sources (→ massive black holes) with masses 106-9  Msun and luminosities ~ 1043-48Lsun; while in the other extreme, → young stellar objects jets have typical sizes ≤ 1 pc, velocities ≤ 10-3 c, and emerge from low mass protostars with masses ~ 1 Msun and luminosities (0.1-2 × 104) Lsun. Jets play an important → feedback role in the evolution of their host systems. See also: → jet launching.
Fr.: objet astrophysique
Pertaining to the physical sciences, especially physics.
Fr.: adsorption physique
Same as → physisorption.
šimi-ye fiziki (#)
Fr.: chimie physique
The branch of chemistry dealing with the relations between the physical properties of substances and their chemical composition and transformations.
Fr.: condition physique
The state of a → physical system regarding its temperature, density, pressure, etc. at a given time.
pâyâ-ye fiziki (#)
Fr.: constante physique
A fundamental → physical quantity that is generally believed to be both universal in nature and constant in time.
Fr.: dimension physique
Any of basic physical quantities, such as mass, length, time, electric charge, and temperature in terms of which all other kinds of quantity can be expressed.
qânun-e fiziki (#)
Fr.: loi physique
A theoretical principle which is deduced from particular observational facts regarding the behavior of matter. Physical laws are expressed by a general statement that a particular → physical phenomenon always occurs if certain → conditions are present.
halâzân-e fiziki, roxgard-e ~
Fr.: libration physique
A real periodic variation in the rotation rate of a celestial object, as distinct from a → geometrical libration. In particular, slight oscillations in the → Moon's rotation caused by the → gravitational attraction of the Earth on the → equatorial bulge of the Moon's near side. The Moon's physical libration is about 0.03° in longitude and about 0.04° in latitude.
Fr.: optique physique
The branch of optics concerned with the wave properties of light, → diffraction, → polarization, and other phenomena for which the ray approximation of → geometric optics is not valid. Also called → wave optics.
Fr.: paramètre physique
padide-ye fiziki (#)
Fr.: phénomène physique
candâ-ye fiziki (#)
Fr.: quantité physique
A physical → property that can be measured and/or calculated.
Fr.: système physique
A set of physical components chosen to study their relations.