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

The full width of a → profile (spectral line or a cross-cut in an image component) at half-maximum intensity.

→ full; → width; → half; → maximum.

Pahnâ, → width; nim, → half; bišiné, → maximum.

The point x = c in an → interval where the value of the → function  f(y) is larger than the value anywhere else in that interval. In other words, f(c) ≥ f(x) for all x in the interval.

→ local; → maximum.

The greatest value attained (or attainable) by a function; the opposite of minimum.

From L. maximum, neuter of maximus "greatest," superlative of magnus "great, large" cognate with Pers. meh "great, large" (Mid.Pers. mah, mas; Av. maz-, masan-, mazant- "great, important," mazan- "greatness, majesty," mazišta- "greatest;" cf. Skt. mah-, mahant-; Gk. megas; PIE *meg- "great").

Bišiné, from biš "much, more; great" (from Mid.Pers. veš "more, longer; more frequently," related to vas "many, much" (Mod.Pers. bas); O.Pers. vasiy "at will, greatly, utterly;" Av. varəmi "I wish," vasô, vasə "at one's pleasure or will," from vas- "to will, desire, wish") + -in superlative suffix + -é nuance suffix.

The density of pure water occurring at 3.98 °C, which is 1.0000 g cm^-3, or 1000 kg m^-3. Water when cooled down contracts normally until the temperature is 3.98 °C, after which it expands. Because the maximum density of water occurs at about 4 °C, water becomes increasingly lighter at 3 °C, 2 °C, 1 °C, and 0 °C (→ freezing point). The density of liquid water at 0 °C is greater than the density of frozen water at the same temperature. Thus water is heavier as a liquid than as a solid, and this is why ice floats on water. When a mass of water cools below 4 °C, the density decreases and allows water to rise to the surface, where freezing occurs. The layer of ice formed on the surface does not sink and it acts as a thermal isolator, thus protecting the biological environment beneath it. This property of water liquid is very unusual; molecules pack more closely than in the crystal structure of ice. The reason is that → hydrogen bonds between liquid water are not stable, they are continuously broken and new bonds are created. In the crystal structure of ice molecules have a fixed pattern creating empty space between molecules.

→ maximum; → density; → water.

A deconvolution algorithm which functions by minimizing a smoothness function in an image. The MEM seeks to extract as much information from a measurement as is justified by the data's signal-to-noise ratio.

→ maximum; → entropy; → method.

Of a → supernova, → peak luminosity.

→ maximum; → light.

A statistical procedure based on choosing the value of the unknown parameter under which the probability of obtaining an observed sample is highest.

→ maximum; → likelihood.

The month(s) during the 11 year → solar cycle when the number of → sunspots reaches a maximum.

→ solar; → maximum.