Fr.: émetteur d'alpha
An atomic nucleus decaying by an → alpha particle emission.
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.
Fr.: courant intermittent
A unidirectional electric current that flows and ceases to flow at irregular or regular intervals.
Lyman alpha emitting galaxy (LAEs)
kahkešân-e gosilande-ye Lyman-alpha
Fr.: galaxie émettrice de Lyman alpha
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).
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).
Past participle of → permit.
Fr.: raie permise
An ordinary spectral line emitted by atoms undergoing energy transitions that are allowed by the selection rules of quantum mechanics. → forbidden lines.
Fr.: transition permise
A transition between two quantum mechanical states that does not violate the quantum mechanical selection rules.
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.
Fr.: comité des utilisateurs
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.
Komité, loan from Fr.; kârbarân plural of kârbar→ user.