An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

An atomic nucleus decaying by an → alpha particle emission.

→ alpha; → emitter.

Any device used to emit light, sound, electrons, or the like.

Agent noun of → emit.

A property of a turbulent dynamical system which is characterized by chaotic, irregular behavior occurring between quiet (or less irregular) periods. In other words, a → turbulent flow having a large → Reynolds number undergoes a phenomenon in which its turbulent activity at a fixed location stops from time to time and starts again. In fact → turbulence never completely disappears, but it can become extremely weak interrupted irregularly by bursts of strong turbulence (see also → developed turbulence). For intermittent flows → probability density functions are not → Gaussian. Turbulent intermittency plays a fundamental role in fields ranging from combustion physics, chemical engineering, meteorology, to astrophysical systems, more specifically the → interstellar medium.

From L. intermittent, pr.p. of intermittere "to leave a space between, drop (for a while), leave off," from → inter- + mittere "to send, let go."

Raftomând, literally "to go and to stop," from raft past stem of raftan "to go, walk, proceed" (present stem row-); Mid.Pers. raftan, raw-, Proto-Iranian *rab/f- "to go; to attack") + -o- euphonic infix + mând past stem of mândan "to remain, stay, relinquish, leave" (Mid.Pers. mândan "to remain, stay," mân "house, home;" O.Pers. mān- "to remain, dwell;" Av. man- "to remain, dwell; to wait;" cf. Gk. menein "to remain;" L. manere "to stay, remain, abide," mansio "a staying, a remaining, night quarters, station" (Fr. maison, ménage; E. manor, mansion, permanent; PIE *men- "to remain, wait for").

Alternately ceasing and beginning again; adj. of → intermittency.

Adjective of → intermittency.

A unidirectional electric current that flows and ceases to flow at irregular or regular intervals.

→ intermittent; → current.

A galaxy belonging to an important population of low mass → star-forming galaxies at → redshift z > 2. Their number increases with redshift. A large fraction of the → dwarf starburst galaxies during the → reionization epoch may be intrinsic LAEs, but their Lyα photons can be scattered by the → neutral hydrogen (H I) in the → intergalactic medium (IGM), which makes Lyα line a powerful probe of reionization. These high-z LAEs have low → metallicity, low stellar masses, low dust → extinction, and compact sizes. The current best nearby analogs of high-z LAEs are → Green Pea galaxies (Yang et al, 2017, arxiv/1706.02819 and references therein).

→ Lyman alpha line; → emit; → -ing; → galaxy.

A → glove that leaves the lower ends of the fingers bare, especially a long one made of lace or other fancy material and worn by women (Dictionary.com). → mitten.

→ mitten.

Dastpuš, from dast, → hand, + puš present stem of pušidan "to cover, to put on," → envelope.

A hand covering enclosing the four fingers together and the thumb separately (Dictionary.com). → glove, → mitt.

M.E. miteyn, from M.Fr., O.Fr. mitaine, from from O.Fr. mite "mitten," and from M.L. mitta.

Dasmtuž, literally "hand-shoe" (Ger. Handschuh, "glove," literally "hand-shoe"), from dast, → hand, + Muž, variant of Pers. muzé "shoe," Mid.Pers. môg "shoe, boot;" cf. Pers. paymôz- / paymôxtan "to dress;" Av. (+ pati-paitišmaoc- "to shoe;" Proto-Ir. *(h)mauc-? "to dress, clothe" (Cheung 2007).

Allowed. → permitted line; → permitted transition.

Past participle of → permit.

An ordinary spectral line emitted by atoms undergoing energy transitions that are allowed by the selection rules of quantum mechanics. → forbidden lines.

→ permitted; → line.

A transition between two quantum mechanical states that does not violate the quantum mechanical selection rules.

→ permitted; → transition.

A measure of the ability of a material to transmit (or "permit") an electric field. Permittivity is defined as the ratio of the flux density produced by an electric field in a given dielectric to the flux density produced by that field in a vacuum. In → SI units, permittivity is measured in → farads per meter. The constant ε₀ is known as the permittivity of free space; its value is about 8.854 x 10^-12 F/m.

State or quality noun from → permit.

A device or equipment which converts audio, video, or coded signals into modulated radio frequency signals which can be propagated by electromagnetic waves.

Agent noun of → transmit.

A committee whose members represent the astronomers who use the facilities of an observatory and which is intended to improve the interaction between the observatory and the users.

→ user; committee, M.E., from O.Fr. commettre "to commit," from L. committere "to bring together," from → com- + mittere "to put, send."

Komité, loan from Fr.; kârbarân plural of kârbar→ user.