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

A member of an extremely luminous population of → high-redshift galaxies which are detected in → submillimeter waves (→ flux density at 850 μm ≥ 3 - 5 mJy). SMGs are powered primarily by star formation rather than an → active galactic nucleus (AGN). Because of their high → dust content, these galaxies emit almost all of their luminosity in the infrared, with a → bolometric luminosity ranging from 10¹²-10¹³ → solar luminosities. As such, SMGs resemble → ultraluminous infrared galaxies (ULIRGs), which are almost exclusively → merging galaxies. Indeed, many observations support a → merger origin for SMGs (see, e.g. C.C. Hayward et al. 2011 and references therein, astro-ph/1101.0002).

→ submillimeter; → galaxy.

That part of the → electromagnetic radiation with a → wavelength beyond 300 → microns.

→ submillimeter; → radiation.

An electromagnetic wave having wavelengths less than one millimeter (frequencies greater than 300 gigahertz).

→ millimeter; → wave.

An act or instance of submitting. The condition of having submitted. → submit

Verbal noun of → submit.

To present for the approval, consideration, or decision of another or others. For example, to submit a research paper for publication, to submit an observing proposal.

From L. submittere "to yield, lower, let down, put under, reduce," from → sub- "under" + mittere "to let go, send."

Dar sepordan, dar sepârdan "to yield, surrender, give in," from dar "in, into" (→ in-) + sepordan/sepârdan "to give in charge, entrust to, deposit with;" ultimately Proto-Iranian *spar- "to hand over, entrust."

A proof that occurs within the context of a larger proof

→ sub-; → proof.

Describing a system or situation for which the → Lorentz factor, γ, is much smaller than 1. See also → ultrarelativistic.

→ ultra- + → relativistic

1) Math.: An → index (a digit or symbol) written under and to the right of a letter for representing terms in a → sequence or → series, or indicating variable components in → tensor analysis. → superscript.
2) Chemistry: Such a number occurring in a chemical formula.

From L. subscriptus, p.p. of subscribere "to write underneath," from → sub- "underneath" + scribere "to write," → describe.

Zirnevešt, from zir-, → sub-, + nevešt "written," from neveštan, nevis- "to write;" Mid.Pers. nibištan, nibes- "to write;" Av./O.Pers. nī- "down; in, into," → ni- (PIE), + paēs- "to paint; to adorn," paēsa- "adornment" (Mid.Pers. pēsīdan "to adorn"); O.Pers. pais- "to adorn, cut, engrave" (Mod.Pers. pisé "variegated"); 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."

A set of elements wholly contained in another set. If each element of a set A belongs to a set B, A is called a subset of B, written A ⊂ B or B ⊃ A and read "A is contained in B" or "B contains A" respectively.

→ sub- + → set.

A set of electrons with the same angular momentum quantum number, denote l. The number of electrons permitted in a subshell is equal to 2l + 1.

→ sub- + → shell.

The point of the surface of a celestial body (including the Earth) at which the Sun is directly overhead at a particular time.

→ sub-; → solar; → point.

Describing a speed that is less than the speed of sound in the medium concerned. → supersonic.

→ sub-; → sonic.

A flow in which the velocity of the constituting particles never exceeds that of sound in the same fluid. Also called subcritical flow.

→ subsonic; → flow.

1) That of which a thing consists; physical matter or material.
2) Physics: A species of matter, commonly homogeneous, that occurs in macroscopic amounts.
3) Philo.: That by virtue of which a thing has its determinate nature, which makes it what it is, as distinguished from something else.

M.E., from O.Fr. substance, from L. substantia "being, essence, material," from substans, pr.p. of substare "to stand under or be present," from → sub- "up to, under" + stare "to stand," cognate with Pers. istâdan "to stand," as below.

Zirist, literally "to stand under," from zir-, → sub-, + ist "to stand; to be standing, "from istâdan "to stand;" Mid.Pers. êstâtan; O.Pers./Av. sta- "to stand, stand still; set;" Av. hištaiti; cf. Skt. sthâ- "to stand;" Gk. histemi "put, place, weigh," stasis "a standing still;" L. stare "to stand;" Lith. statau "place;" Goth. standan; PIE base *sta- "to stand."

Grammar: A word or word group functioning syntactically as a noun. Substantives include nouns and → nominals.

M.E., from L.L. substantivus "of substance or being," from L. substantia "being, essence, material," → substance, contraction of "noun substantive" from L. nomen substantivum ("independent noun") as opposed to nomen adiectivum "noun adjective" ("dependent noun").

Ziristin, from zirist, → substance, + -in a suffix of relation.

1) Pertaining to a class of objects with a mass less than 8 percent that of the Sun.
2) → substellar point.

→ sub- + → stellar.

The mass limit below which → hydrogen fusion cannot take place, and the cloud collapse cannot lead to the formation of a star. The limit is 0.075 → solar masses, corresponding to about 80 Jupiter masses.

→ substellar; → limit.

An object with a mass too small to sustain the → proton-proton chain and thus become a true star. See → brown dwarf.

→ substellar; → object.

The point on the Earth, or other body, at which a particular star is directly overhead at a given time.

→ substellar; → point.

The fact or condition, for an object, of not being capable to sustain the → hydrogen fusion because of its low mass (less than 0.08 → solar masses).

→ substellar + → -ity.