Hot, O.E. hat, "hot; fervent, fierce," from P.Gmc. *haitoz (cf. Du. heet, Ger. heiß "hot," Goth. heito "heat of a fever").
Dâq "hot; brand, marking," from Mid.Pers. dâq, dâk "hot," dažitan
"to burn, scorch," dažišn "burning"
(Mod.Pers. dežan (
hot accretion flow
tacân-e farbâl-e dâq
Fr.: écoulement d'accrétion chaud
A type of → accretion flow by a → compact object such as a → black hole which has a high → virial temperature, is → optically thick, and occurs at lower mass → accretion rates compared with → cold accretion flows. In a hot accretion flow with a very low mass accretion rate, the electron mean free path is very large, and so the accreting → plasma is nearly collisionless. In this type of accretion flow, thermal conduction transports the energy from the inner to the outer regions. As the gas temperature in the outer regions can be increased above the → virial temperature , the gas in the outer regions can escape from the gravitational potential of the central black hole and form outflows, significantly decreasing the mass accretion rate.
Fr.: cœur chaud
Same as → hot molecular core.
Fr.: petit cœur chaud
A warm, compact → molecular clump found in the inner envelope of a → Class 0 → protostar. Hot corinos are low-mass analogs of → hot molecular cores (HMCs) occurring in → massive star formation sites. With a typical size of ≤ 150 → astronomical units, hot corinos are two orders of magnitude smaller than HMCs. They have densities ≥ 107 cm-3 and temperatures ≥ 100 K (Ceccarelli, C. 2004, ASP Conf. Ser. 323, 195).
hot dark matter
mâdde-ye târik-e dâq (#)
Fr.: matière noire chaude
hot dust-obscured galaxy (HDOG)
kahkešân-e tiré bâ qobâr-e dâq
Fr.: galaxie obscure à poussière chaude
A member of the most extreme galaxies in terms of their luminosities and unusual hot → dust temperatures. The → infrared emission from HDOGs is dominated by obscured accretion onto a central → supermassive black hole (SMBH), in most cases without significant contribution from → star formation. The large contrast between the underlying → host galaxy and the hyper-luminous emission from the → active galactic nucleus (AGN) implies that either the SMBH is much more massive than expected for the stellar mass of its host, or is radiating well above its → Eddington limit. The most extreme of these remarkable systems known is → W2246-0526.
hot electron diode
diod-e elektron-e dâq
Fr.:diode à électrons chauds
Same as → Schottky diode
Fr.: Jupiter chaud
A giant, gaseous, Jupiter-like planet lying too close to its parent star and having an orbital period from a few days to a few weeks. The existence of hot Jupiters is usually interpreted in terms of planetary migration. These planets can, in principle, be formed at larger distances from their stars and migrate to the inner regions due to dynamical interaction with the proto-planetary disk.
hot molecular core (HMC)
maqze-ye molekuli-ye dâq
Fr.: cœur moléculaire chaud
A relatively small, dense, and hot → molecular clump occurring in regions of → massive star formation. HMCs have diameters ≤ 0.1 pc, densities ≥ 107 cm-3, and temperatures ≥ 100 K. The densest hot cores are traced in → ammonia (NH3) and possess densities of 108 cm-3, sizes down to 0.05 pc and temperatures of up to 250 K. Hot molecular cores are generally associated with → compact H II regions and → ultracompact H II regions. High angular resolution observations suggest that HMCs are internally heated by embedded sources, since temperature and density increases toward the center as expected if star formation is occurring close to the core center. Same as → hot core.
Fr.: pixel chaud
Of a → CCD detector, a pixel that has higher charge loss. Hot pixels are a type of noise affecting almost every CCD camera. They are caused by small contamination or production faults in the CCD sensor area.
lekke-ye dâq (#)
Fr.: point chaud
A compact, highly luminous region in a cataclysmic binary located in the accretion disk where the stream of material hits it.
setâre-ye dâq (#)
Fr.: étoile chaude
A member of a class of stars having high → effective temperatures (above some 15,000 K); mainly → massive stars, but also including → exciting stars of → planetary nebulae, → white dwarfs, and → symbiotic stars.
The 24th part of a day; 60 minutes.
Hour, from M.E. houre, from O.Fr. hore, from L. hora "hour, time, season," from Gk. hora "any limited time," used of day, hour, season, year; cognate E. → year.
Sâ'at, from Ar.
zâviye-ye sâati (#)
Fr.: angle horaire
A telescope based coordinate specifying the angle, in the equatorial plane, from the meridian to a plane containing the celestial object and the north and south celestial poles.
parhun-e sâ'ati, dâyere-ye ~
Fr.: cercle horaire
sâat-e šeni (#)
A device for measuring time; it consists of a glass container having two compartments from the uppermost of which a quantity of sand runs in an hour into the lower one through a narrow tube.
Sâat-e šeni, from sâat, → hour + šeni, adj. of šen "sand."
1) A building in which people live.
M.E. h(o)us, from O.E. hus "dwelling, shelter, house;" cf. O.N. hus; Du. huis; Ger. Haus .
Xâné "house," from Mid.Pers. xânak, xân, xôn; Aftari dialect kiye "house, home;" Xonsâri ki "house;" Anâraki xiya, Tâti Karingân kâ, Sangesari keh "house, home;" cf. L. cunae "cradle; bed;" Gk. kome "village;" PIE base *kei- "bed; to lie, to settle; beloved" (other cognates: O.E. ham "dwelling, house, village;" E. home; Ger. Heim; L. civis "townsman;" Fr. cité; E. city; Skt. śiva- "auspicious, dear").
parjâ zadan, parjâyidan
1) To remain in one place in the air by rapidly beating the wings.
M.E. hoveren, frequentative of hoven "hover, tarry, linger," of unknown origin.
Parjâ zadan (on the model of darjâ zadan "to march in the same place, moving one's legs up and down without going forward"), from par zadan darjâ "to beat the wings at the same place," from par zadan "to beat the wings," from par "wing, → feather," zadan, → beat, + darjâ "in the same place," from dar, → in, + jâ, → place.
A vehicle capable of travelling over land or water on a cushion of air.
Fr.: vol stationnaire
The act of one who hovers.