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

A sort of → greenhouse effect in → stellar atmospheres where the deeper layers heat up due to overlying → opacity. The presence of numerous → bound-bound opacities of → metals amplifies the → scattering of → photons, in particular their → backscattering, forcing the → temperature to increase in order to conserve the radiation flux and the transport of energy from the interior to the outer parts of the atmosphere.

→ back; → warming; → effect.

An increase in the average → temperature of the Earth's → atmosphere that brings about climatic changes.

→ global; → warming.

Moderately warm; tepid.

M.E. lukewarme "tepid," from luke "tepid," of unknown origin, + → warm.

Velarm "lukewarm, tepid," of unknown origin.

A relatively dense collection of meteoroids at certain spots along some → meteoroid streams.

→ meteoroid; → swarm.

A great number of things especially in motion. → meteorite swarm.

ME; OE swearm; cf. O.S., M.L.G. swarm, Swed. svärm, M.Du. swerm, O.H.G. swarm, Ger. Schwarm "swarm;" O.N. svarmr "tumult."

Qang in Lârestâni "swarm of bees, flies, or the like," Lori qem (qem zaye) "swarm of bees, ants, and the like."

Moderately hot.

M.E.; O.E. wearm (cf. O.S., O.Fris., M.Du., O.H.G., Ger. warm, O.N. varmr, Goth. warmjan "to warm"); cognate with Pers. garm, as below.

Garm "warm;" Mid.Pers. garm "warm;" O.Pers. garma-pada "name of the fourth month" (June-July); Av. garəma- "warm; heat;" cf. Skt. gharmá "heat;" Gk. therme, thermos; L. formus "warm;" E. warm, as above; PIE base *ghworm-/*ghwerm- "warm."

A cloud of ionized gas within → active galactic nuclei (AGN) that causes absorption at → soft X-ray wavelengths. Warm absorbers were first suggested by Halpern (1984) to explain Einstein data of the quasar MR 2251-178. They are dubbed "warm" absorbers as they imply gas at temperatures of 10⁴-10⁵ K; the gas is → photoionized, not collisionally ionized. High resolution observations of warm absorbers have shown that they are outfowing. See also → cold absorber (Ceri Ellen Ashton, 2005, A Study of Warm Absorbers in Active Galactic Nuclei, Thesis, Mullard Space Science Laboratory Department of Space and Climate Physics University College London ).

→ warm; → absorber.

Meteo.: A leading edge that advances in a mass of air and replaces cooler air by warm air.

→ warm; → front.

A component of the → interstellar medium consisting of an extremely tenuous (density 0.1 to 10 cm^-3) and relatively warm gas (temperature about 8,000 K) filling the space between denser neutral and ionized gas. Hydrogen is partly ionized, partly atomic and observed by the → 21-centimeter line in emission.

→ warm; → intercloud medium.

The space containing a cluster of galaxies filled with a tenuous gas of temperature 10⁵ to 10⁷ K and density 10^-6 to 10^-4 cm^-3. WHIM has been continuously shock-heated during the process of structure formation. It is so highly ionized that it can only absorb or emit far-ultraviolet and soft X-ray photons, primarily at spectral lines of highly ionized C, O, Ne, and Fe. WHIM is thought to be the main reservoir of missing baryons.

→ warm; → hot; → intergalactic medium.

The process of becoming warmer; a rising temperature. → backwarming, → heating.

→ warm; → -ing.