Fr.: continuum de Balmer
A continuous range of wavelengths in the Balmer spectrum of
hydrogen corresponding to transitions between the energy levels
Fr.: continuum bleu
The → continuum emission of an astronomical source with wavelengths between about 492 and 455 nm.
A continuous extent or succession, which has no discrete parts, as the continuum of real numbers as opposed to the sequence of discrete integers. → continuum emission.
From L. neut. of continuus, → continuous
Peyvastâr, from peyvast past tense stem of peyvastan "to connect, join," Mid.Pers. paywastan, from *pati-basta-, from suffix pati- (Mid.Pers. pât-, from O.Pers. paity "agaist, back, opposite to, toward, face to face, in front of," Av. paiti, akin to Skt. práti "toward, against, again, back, in return, opposite," Pali pati-, Gk. proti, pros "face to face with, toward, in addition to, near;" PIE *proti) + basta- "tied, shut" (Av./O.Pers. band- "to bind, fetter," banda- "band, tie," Skt. bandh- "to bind, tie, fasten," PIE *bhendh- "to bind," cf. Ger. binden, E. bind), cf. Skt. prati-bandh- "to tie." + -âr suffix forming verbal noun.
Fr.: émission continuum
A continuous radiation produced by three processes: radiative recombination due to transition between electron free-free states, two-photon decays of metastable levels, and thermal bremsstrahlung.
→ continuum; → emission.
Fr.: vent induit par continuum
The transfer of photon momentum to free electrons. The acceleration by → continuum emission can be given by: ac = (σ/m)(L*/4πR2c), where σ is the → Thomson scattering → cross section, m is the mass per free electron, L* is → stellar luminosity, R* is radius, and c the → speed of light. The ratio of ac to the → surface gravity is ≅ 2 × 10-5L*/M*, with M* and L* in solar units. The atmosphere is is stable if ac very smaller than ggrav. If L* is above the → Eddington limit, the radiation pressure in the continuum leads to very heavy → mass loss and thus to expanding envelopes (K.S. de Boer & W. Seggewiss, 2008, Stars and Stellar Evolution, EDP Sciences).
peyvastâr-e Lyman (#)
Fr.: continuum de Lyman
A continuous range of wavelengths in the spectrum of hydrogen at wavelengths less than the → Lyman limit. The Lyman continuum results from transitions between the → ground state of hydrogen and → excited states in which the single electron is freed from the atom by photons having an energy of 13.6 eV or higher.
Lyman continuum escape
goriz-e peyvastâr-e Lyman
Fr.: échappement du continuum de Lyman
The process whereby → Lyman continuum photons produced by → massive stars escape from a galaxy without being absorbed by interstellar material. Some observations indicate that the Lyman continuum escape fraction evolves with → redshift.
Fr.: continuum nébulaire
The part of a nebular object's → spectrum that is created by → free-free emission.
radio continuum emission
gosil-e peyvastâr-e râdio-yi
Fr.: émission de continuum radio
A → continuum emission with frequencies in the radio range of the electromagnetic spectrum.
Fr.: continuum de recombinaison
A recombination radiation that is continuous over a range of frequencies. Same as → continuum emission.
→ recombination; → continuum.