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Number of Results: 9 Search : Jeans

Jeans Jeans Fr.: Jeans Named after Sir James Hopwood Jeans (1877-1946), English mathematical physicist, astrophysicist, and popularizer of science. He made important contributions to theoretical astrophysics, especially to the theory of stellar formation. |

Jeans instability nâpâydâri-ye Jeans Fr.: instabilité de Jeans An instability that occurs in a → → |

Jeans length derâzâ-ye Jeans (#) Fr.: longueur de Jeans The critical size of a homogeneous and isothermal interstellar
cloud above which the cloud is unstable and must collapse under its own gravity.
Below this size the cloud's internal pressure is sufficient to resist collapse.
The Jeans length is defined by:
^{2}/Gρ)^{1/2}
= 0.2 pc (T/10 K)^{1/2}(n/10_{H2}^{4}
cm^{-3})^{-1/2},
where c is the → _{s}sound speed, G is the
→ gravitational constant, ρ is the gas density,
T is the gas temperature, and n is the
molecular hydrogen density._{H2} |

Jeans mass jerm-e Jeans (#) Fr.: masse de Jeans The → ^{5/2} / 6) G^{ -3/2}ρ_{0}^{-1/2}c_{s}^{3}, where G is the
→ gravitational constant, ρ_{0} the
initial → density,
and c the isothermal → _{s}sound speed.
It can be approximated to M
~ 45 (_{J}T_{K}) ^{3/2} (n_{cm-3})^{ -1/2}
in units of solar masses, where T_{K} is the temperature in
→ Kelvin, and
n_{cm-3} the gas density per cm^{3}. High density favors
collapse, while high temperature favors larger Jeans mass. See also:
→ thermal Jeans mass,
→ turbulent Jeans mass. |

Jeans scale marpel-e Jeans Fr.: échelle de Jeans Same as → |

Rayleigh-Jeans law qânun-e Rayleigh-Jeans(#) Fr.: loi de Rayleigh-Jeans A classical law approximately describing the intensity of radiation
emitted by a → |

Rayleigh-Jeans spectrum binâb-e Rayleigh-Jeans Fr.: spectre Rayleigh-Jeans The part of → |

thermal Jeans mass jerme-e Jeans-e garmâyi Fr.: masse de Jeans thermique The → |

turbulent Jeans mass jerm-e Jeans-e âšubnâk Fr.: masse de Jeans turbulente The characteristic mass for → |