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

1a) To bring together into a one body or place.
1b) To gather and gradually accumulate in a place.
2) to gather together; assemble.

From O.Fr. collecter, from L. collectus, p.p. of colligere "gather together," from → com- "together" + legere "to gather," cf. L. lignum "wood, firewood," lit. "that which is gathered"; cognate with Gk. legein "to say, tell, declare," from PIE *leg- "to pick together, gather, collect"

1) Gerdâvardan "to collect," from gerd "round; around," → disk; alternatively, ultimately from PIE base *ger- "to gather," cf. Iranian ger-, gor-, etc. "to gather," → category, + âvardan "to bring," → production.
Anbâštan, anbârdan "to fill, to replete;" Mid.Pers. hambāridan "to fill;" from Proto-Iranian *ham-par-, from prefix ham-, → com-, + par- "to fill;" cf. Av. par- "to fill," parav-, pauru-, pouru- "full, much, many;" O.Pers. paru- "much, many;" Mid.Pers. purr "full;" Mod.Pers. por "full, much, very;" PIE base *pelu- "full," from *pel- "to be full;" cf. Skt. puru- "much, abundant;" Gk. polus "many," plethos "great number, multitude;" O.E. full.
2) Gerdâmadan "to come together," with âmadan "to come," → efficiency.

A → sequential star formation model involving → massive stars and → H II regions. The energetic ultraviolet photons from a massive star born in a → molecular cloud drive a spherical → ionization front radially outward from the star at a velocity much higher than the → sound speed in the cold neutral gas. The supersonic expansion of the H II region through the surrounding neutral gas creates a → shock front, sweeping up an increasingly massive and dense shell of cool neutral gas. This is the collect phase of the process in which the H II region simply acts like a snowplough. If the expansion of the H II region continues for long enough, the surface density of the shell increases to the point where the shell becomes self-gravitating. The shell is then expected to collapse and fragment. Individual fragments may then enter a non-linear collapse phase, possibly forming massive stars. This model was first proposed by Elmegreen & Lada (1977, ApJ 214, 725), who used a one-dimensional analysis. Whitworth et al. (1994, MNRAS, 268, 291) developed an analytical model for the collect and collapse process which predicts the fragmentation time, the size, number, and mass of the fragments (see also Elmegreen 1998, in ASP Conf. Ser. 148, Origins, eds. Woodward et al., p. 150 and references therein). → stimulated star formation, → triggered star formation.

→ collect; → collapse; → model.

Of an interferometric telescope made up of several mirrors, the hypothetical mirror created by the combination of the individual mirrors.

→ collect; → area.

1) The act or process of collecting.
2) A group of objects or works to be seen, studied, or kept together.

Verbal noun from → collect.

Forming a whole; of or characteristic of a group taken together.

→ collect + → -ive.

1) The whole behavior of a system of many interacting components, which differs from that of the individual components. Some classical examples are the → many-body problem, → phase transition, most of thermodynamic phenomena, collective oscillations occurring in solids, etc. Physics dealt with collective behavior much earlier than the term collective behavior was even coined.
2) Sociology: The more or less unpredictable act of people when being in group, which is totally different from the behavior they would have if acted individually.
3) Biology: A large number of group phenomena such as pattern formation, self organization, trail formation, and synchronization seen among many living creatures.

→ collective; → behavior.

Formation of stars, especially → massive stars, in group as opposed to individual formation.

→ collective; → star; → formation.

1) The principle of ownership of the means of production, by the state or the people.
2) A social system based on this principle (Dictionary.com).

→ collective; → -ism.

1) Collective character.
2) A collective whole.

→ collective; → -ity.

The process of forming collectives or collective communities where property and resources are owned by the community and not individuals (TheFreeDictionary.com).

Verbal noun of → collectivize.

To organize (a people, industry, economy, etc.) according to the principles of → collectivism (Dictionary.com).

→ collective; → -ize.

A device that collects: a solar energy collector; a dust collector.
The semiconductor region in a bipolar junction transistor in which most of the current flows.

From → collect + -or.

1) To strike together with forceful impact, such as two astronomical objects.
2) Of two or more atomic particles, to approach closely resulting in an abrupt change of momentum or exchange of energy.

From L. collidere "to strike together," from col- variant of → com- "together" + laedere "to strike," of unknown origin.

Ham- "together, with," → com- + kubidan, kuftan "to beat, strike, pound," kus "drum," Mid.Pers. kôftan and kôstan "to beat, strike."

A particle accelerator in which two beams of particles are forced to collide head on.

Agent noun from → collide + → -or.

Same as → collider.

→ collide; → beam; → accelerator.

To pack and align photons or atomic particles parallel to a particular direction.

L. collimatus, p.p. of collimare, alteration of collineare "to make straight," from → com- + linea, → line.

From ham- "together, with," → com- + râstâ, → direction, + -idan infinitive suffix, kardan "to do," → work.

Made accurately parallel or brought into line.

Past participle of → collimate.

A → beam of → photons or → subatomic particles with a narrow → cross section that has little or no spatial spread.

→ collimated; → beam.

A beam of particles in which every particle would have exactly the same direction of travel, thereby the jet moves without → dispersion. Collimated jets of → plasma are associated with → protostars.

→ collimated; → jet.

1) The process of restricting a beam of photons or particles to a given area.
2) The process of adjusting a telescope to place all optical elements in precise alignment. → align a telescope.

Verbal noun of → collimate.