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

A range of infrared wavelengths to which the Earth's atmosphere is relatively transparent, and at which observations can be made from the ground. Infrared windows are found near wavelengths of 1.25, 1.65, 2.2, 3.6, 5.0, 10, 20, and 30 microns, and beyond 300 microns.

→ infrared; → window.

A sound wave whose frequency is below the audible range of about 20 → Hz to 20,000 Hz. → sound wave; → ultrasound; → subsonic.

→ infra- + → sound.

That which enters into a → compound or → mixture.

M.E., from L. ingredient- (nominative ingrediens) "that which enters into," p.p. of ingredi "to go in, enter," from → in- + gradi "to go, to walk," → egress.

Darâné, literally "brought into," from dar-, → in-, + ân present stem of ânidan "to bring, to lead," → relate, + nuance suffix -é.

Same as → immersion.

From → in- + gress, → egress.

To take or receive (property, a right, a title, etc.) by succession or will, as an → heir (Dictionary.com).

→ heritage.

1) Capable of being inherited.
2) Capable of inheriting; qualified to inherit (Dictionary.com).

→ inherit; → -able.

1) Something that is or may be inherited; property passing at the owner's death to the heir or those entitled to succeed; legacy; something, as a quality, characteristic, or other immaterial possession, received from progenitors or predecessors as if by succession.
2) The genetic characters transmitted from parent to offspring, taken collectively.
3) The act or fact of inheriting by succession, as if by succession, or genetically (Dictionary.com).

Verbal noun of → inherit.

A person who → inherits; → heir.

→ inherit; → -or.

The condition or an instance of not being homogeneous.

→ in- "not" + → homogeneity.

Lack of homogeneity; something that is not → homogeneous.

→ in- "not" + → homogeneous.

Of, pertaining to, or occurring at the beginning.

Initial, from L. initialis, from initium "a beginning, an entrance," from p.p. stem of inire "to go into, begin," from → in- + ire "to go," → ion.

Âqâzin "pertaing to the beginning," from âqâz "beginning," from Proto-Iranian *āgāza-, from prefix ā- + *gāz- "to take, receive," cf. Sogdian āγāz "beginning, start," pcγz "reception, taking."

1) Conditions at an initial time t = t₀ from which a physical system or a given set of mathematical equations evolves.
2) Meteo.: A prescription of the state of a → dynamical system at a specified time; for all subsequent times, the → equation of motion and → boundary conditions determine the state of the system.

→ initial; → condition.

The mass of a star at its arrival on the → main sequence.

→ initial; → mass.

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 ≤ M_solar < 0.5; α = 2.3 for 0.5 ≤ M_solar < 1; α = 2.3 for 1 ≤ M_solar. 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; → mass; → function.

The value of the phase corresponding to the origin of time. Same as the → epoch angle.

→ initial; → phase; → angle.

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.

→ initial; → singularity.

1) The first step or action of a matter; commencing move.
2) An introductory act or step; leading action.

From Fr. initiative, from L. initiatus, p.p. of initiare "to begin," from initium "a beginning," → initial.

Bongâm, from bon "basis; root; foundation; bottom," → fundamental, + gâm "step, pace," → egress.

1) General: To force into a passage, cavity, or tissue.
2) Math.: Verbal form related to → injection.

From L. injectus, p.p. of injicere "to throw in or on," from → in- "in" + -icere, combining form of jacere "to throw."

Daršândan, from darešândan, from dar-, → in, + ešândan, → eject.

1) General: The act of injecting. Something that is injected.
2) Physics: The process of introducing electrons or holes into a semiconductor so that their total number exceeds the number present at thermal equilibrium. → hole injection.
3) Math.: A one-to-one → mapping. In other words, a mapping from a → set A onto a set B such that for every element in B there is at the most an element in A.

Verbal noun of → inject.

Of or pertaining to a → injection.

Adj. related to → injection.