An Etymological Dictionary of Astronomy and Astrophysics
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Altering in the size or shape of a body. See also → deformable.

Verbal noun of → deform.

The process of producing a quantifiable result in a → fuzzy logic system, given → fuzzy sets and corresponding → membership functions. Defuzzification is the last step in a fuzzy logic system. After → fuzzy inferencing, the overall result is a → fuzzy value. This result should be defuzzified to obtain a final → crisp value.

Verbal noun of → defuzzify; → -tion.

The number of electrons a neutral atom has lost in an ionizing physical process (radiation, shock, collision). In spectroscopy, the degree of ionization is indicated by a Roman numeral following the symbol for the element. A neutral atom is indicated by the Roman numeral I, a singly ionized atom, one which has lost one electron, is indicated by II, and so on. Thus O VI indicates an oxygen atom which has lost five electrons.

→ degree; → ionization.

The ratio of the intensity of polarized portion of light to the total intensity at a point in the beam.

→ degree; → polarization.

The act or process or an instance of dehumanizing.

Verbal noun of → dehumanize.

Chemistry: A process in which all charged species are removed from a solution.
The return of an ionized gas to its non-ionized state after the ionizing source has been removed.

From → de- + → ionization.

A mechanism predicted by theoretical models of → supernova explosion that operates after the → supernova shock fails to deliver a → prompt supernova explosion. The delayed supernova explosion mechanism assumes that a few tenth of a second after the → iron core collapse, the supernova shock is stalled due to energy dissipation. The material between the → protoneutron star and the stalled shock is mainly disintegrated into neutrons and protons due to the high temperatures (a few MeV) in this region. As the → neutrinos coming from the protoneutron star run through this material, a fraction of the neutrinos are captured by the → nucleons, and their energy is deposited in the material. As a result, the material behind the shock is heated by the neutrinos. If this neutrino heating is efficient enough, the stalled shock can be reinvigorated to bring about a supernova explosion.

→ delay; → supernova; → explosion.

1) An act or instance of deleting. The state of being deleted. A deleted word, passage, etc.
2) Genetics: A type of chromosomal aberration in which a segment of the chromosome is removed or lost (Dictionary.com).

Verbal noun from → delete.

Same as → Dirac function.

Same as → Mintaka.

→ delta; → Orion.

In communications, the process of recovering the original information from a modulated signal wave. → modulation.

→ de- + → modulation

1) The → act or → circumstance of proving or being → proved conclusively, as by → reasoning or a show of → evidence.
2) Something serving as → proof or supporting evidence.
3) An exhibition, as of feeling; display; → manifestation (Dictionary.com).

Verbal noun of → demonstrate.

The removal of mystery or confusion surrounding a topic or idea.

→ demystify; → -tion.

1) A name or designation.
2) The action of naming or classifying something. 3) One of the grades or degrees in a series of designations of quantity, value, measure, weight, etc. (Dictionary.com).

Verbal noun of → denominate.

→ core mass function.

→ dense; → core; → mass; → function.

In the early Universe, localized enhancements in the density of either matter alone or matter and radiation. According to models, very small initial fluctuations (less than 1 percent) can lead to subsequent formation of galaxies.

→ density; → fluctuation.

An → H II region which lacks enough matter to absorb all → Lyman continuum photons of the → exciting star(s). In such an H II region a part of the ionizing photons escape into the → interstellar medium. See also → ionization-bounded H II region.

→ density; → bounded; → region.

General: The act or process of depleting. The state of being depleted.
Astro.: The process or state of a material which contains less of a particular chemical element or isotope than the expected standard amount.

Noun from → deplete

The region of a semiconductor in which the density of mobile carriers is too low to neutralize the fixed charge density of donors and acceptors.

→ depletion; → layer.

The time it takes for a given → chemical species to be reduced below a significant level of → abundance in a → compound or → object.

→ depletion; → time.