Fr.: flot d'accrétion
1) Flow of matter during an accretion process.
cold accretion flow
tacân-e farbâl-e sard
Fr.: écoulement d'accrétion froid
1) A type of → accretion flow by a
→ compact object
such as a → black hole
that consists of cool → optically thick
gas and has a relatively high mass → accretion rate,
in contrast to → hot accretion flows.
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.