initial mass function (IMF)
karyâ-ye âqâzin-e jerm
Fr.: fonction initiale de masse
A mathematical expression describing the relative number of stars found in different ranges of mass for a cluster of stars at the time of its formation. It is defined as φ(log M) = dN / dlog M ∝ M -Γ, where M is the mass of a star and N is the number of stars in a logarithmic mass interval. The value of the slope found by Salpeter (1955) for → low-mass and → intermediate-mass stars in the → solar neighborhood is Γ = 1.35. The IMF can be expressed also in linear mass units: χ(M) = dN / DM ∝ M -α. Note that χ(M) = (1 / M lm 10) φ(log M), and α = Γ + 1. In this formalism the Salpeter slope is α = 2.35. There is a third way for representing the IMF, in which the exponent is x = -α. The IMF is not a single power law over all masses, from → brown dwarfs to → very massive stars (Kroupa, 2002, Science 295, 82). Different slopes have been found for different mass segments, as follows: α = 1.3 for 0.08 ≤ Msolar < 0.5; α = 2.3 for 0.5 ≤ Msolar < 1; α = 2.3 for 1 ≤ Msolar. The IMF at low masses can be fitted by a → lognormal distribution (See Bastian et al., 2010, ARAA 48, 339 and references therein). See also → canonical IMF.
initial phase angle
zâviye-ye fâz-e âqâzin
Fr.: angle de phase initial
The value of the phase corresponding to the origin of time. Same as the → epoch angle.
takini-ye âqâzin (#)
Fr.: singularité initiale
An instant of infinite density, infinite pressure, and infinite temperature where the equations of general relativity break down, if the standard Big Bang theory is extrapolated all the way back to time zero. → singularity.
1) The first step or action of a matter; commencing move.
From Fr. initiative, from L. initiatus, p.p. of initiare "to begin," from initium "a beginning," → initial.
1) General: To force into a passage, cavity, or tissue.
From L. injectus, p.p. of injicere "to throw in or on," from → in- "in" + -icere, combining form of jacere "to throw."
1) General: The act of injecting. Something that is injected.
Verbal noun of → inject.
Of or pertaining to a → injection.
Adj. related to → injection.
Fr.: crique, bras de mer
A small arm of the sea, a lake, or a river.
From → in- + let "to allow," M.E. leten, O.E. lætan; cognate with Du. laten, Ger. lassen, akin to Gk. ledein "to be weary", L. lassus "tired."
Situated within or farther within; interior.
From O.E. inra, comparative of inne (adv.) "inside;" → in-.
Daruni, adj. of darun "in, into; within" (Mid.Pers. andarôn "inside," from andar, → inter-, + rôn "side, direction;" Av. ravan- "(course of a) river").
Fr.: noyau interne
The central part of the → Earth's core, composed of solidified → iron and → nickel, and extending from a depth of about 5100 km to the center of the Earth, at 6360 km. Its radius is about 1/3 that of the whole core and is effectively decoupled from the → mantle due to the molten nature of the surrounding → outer core. The radius of the inner core is defined by a small increase in → compressional wave velocity at a radius of about 1200 km. Its density is about 12 g/cm3. The → temperature of the inner core has been estimated at 5000-7000 °C.
inner Earth object (IEO)
barâxt-e daruni-ye madâr-e zamin
Fr.: objet interne à l'orbite terrestre
inner Lagrangian point
noqte-ye Lagrange-e daruni (#)
Fr.: point de Lagrange interne
One of the five → Lagrangian points, denoted L1, which lies between the two bodies on the line passing through their center of mass. In a → close binary star system mass transfer occurs through this point.
inner Lindblad resonance (ILR)
bâzâvâyi-ye Lindblad-e daruni
Fr.: résonance de Lindblad interne
A → Lindblad resonance expressed by: Ωp = Ω - κ/m.
sayârehâ-ye daruni (#)
Fr.: planètes internes
The planets Mercury, Venus, Earth and Mars collectively. T hey are also known as the terrestrial planets.
Fr.: éphémérides INPOP
A dynamical model developed in France since 2003 which calculates the motion of → Solar System bodies with the highest accuracy. It integrates data obtained by NASA and ESA space missions. See, for example, A. Fienga et al. 2011, arXiv:1108.5546.
INPOP, short for Intégration Numérique Planétaire de l'Observatoire de Paris; → ephemerides.
dardâd (#), darundâd (#)
1) The current, voltage, or driving force applied to an electric or electronic circuit or
From → in- + put, from M.E. put(t)en "to push, thrust, put;" O.E. *putian.
kâtâlog-e dardâd, ~ darundâd
Fr.: catalogue d'entrée
1) To mark with words, characters, etc., especially in a durable or conspicuous way.
From L. inscribere, from → in- + scribere "to write," from PIE *skreibh- (cf. Gk. skariphasthai "to scratch an outline, sketch;" Lett. skripat "scratch, write;" 0 O.N. hrifa "scratch"); PIE base *sker- "cut, incise."
Darveštan, darvisidan (on the model of neveštan, nevisidan "to write"), from dar-, → in-, + vešt-, vis- (see below) + -idan infinitive suffix. Vešt-, vis- from Mid.Pers. bišt-, bis- (nibištan, nibes- "to write"), from O.Pers. pais- "to adorn, cut, engrave," Av. paēs- "to paint, adorn," paēsa- "adornment," Mid.Pers. pēsīdan "to adorn;" cf. Skt. piśáti "adorns; cuts;" Gk. poikilos "multicolored;" L. pingit "embroiders, paints;" O.C.S. pisati "to write;" O.H.G. fēh "multicolored;" Lith. piēšti "to draw, adorn;" PIE base *peik- "colored, speckled."
Fr.: angle inscrit
An angle whose vertex lies on a circle and whose sides are chords of the circle.
Not secure; exposed or liable to risk, loss, or danger.