An Etymological Dictionary of Astronomy and Astrophysics
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An process in which an excited state returns to the ground state without emitting radiation. → radiative process.

→ non-; → radiative; → process.

Of or pertaining to radiation.

Adjective of → radiation.

The acceleration imparted to matter by → radiation pressure.

→ radiative; → acceleration.

The slowing down of a star's rotation due to radiative momentum transfer caused by emission of electromagnetic radiation.

→ radiative; → braking.

Capture of a free electron by an ion with the subsequent emission of photons; also called → radiative recombination.

→ radiative; → capture.

A collision between charged particles in which part of the kinetic energy is converted into electromagnetic radiation.

→ radiative; → collision.

The process by which temperature decreases due to an excess of emitted radiation over absorbed radiation.

→ radiative; → cooling.

The process when the energy difference between the excited and non excited states of an atom is taken away by radiation.

→ radiative; → decay.

A process of → radiative transfer in which photons are repeatedly absorbed and re-emitted by matter particles.

→ radiative; → diffusion.

A → radiative zone occupying the outer parts of a star.

→ radiative; → envelope.

The balance between radiative emission and radiative absorption in a specified system.

→ radiative; → equilibrium.

The radiative energy put back to the environment through an astrophysical process. For example, in the process of → star formation  → accretion disks form around → protostars. The material in the disk spirals inward and on to the protostar, provided that there is an efficient mechanism to redistribute → angular momentum outward in the disk. During this process → gravitational energy is transformed into radiation due to → viscous dissipation in the disk and at the → accretion shock around the protostar. This radiation heats the region around the protostar and may → suppress subsequent → fragmentation and further star formation. Thus, radiative feedback plays a critical role in regulating the stellar → initial mass function.

→ radiative; → feedback.

The radiative energy per unit time and unit area.

→ radiative; → flux.

The process by which temperature increases due to an excess of absorbed radiation over emitted radiation.

→ radiative; → heating.

A physical process occurring in → stellar atmospheres whereby → radiation pressure selectively pushes certain → chemical elements outward, leading to an atmospheric overabundance of such elements. See also → gravitational settling.

→ radiative; → levitation.

For a → supernova remnant (SNR), same as the → snowplow phase.

→ radiative; → phase.

An process in which an excited state loses its absorbed energy by emission of radiation. → non-radiative process.

→ radiative; → process.

The process by which an ionized atom binds a free electron in a → plasma to produce a new atomic state with the subsequent radiation of photons.

→ radiative; → recombination.

A → shock wave in which the → time-scale for → cooling is much shorter than the appropriate → dynamical or → evolutionary time-scale of the system that drives the shock. Radiative shock waves are believed to play a key role in a variety of different astrophysical environments, including → magnetic cataclysmic variables, → jets from → young stellar objects, → accretion in → T Tauri stars, → colliding stellar winds, and → supernova remnants.

→ radiative; → shock.

The process by which the → electromagnetic radiation passes through a medium that may contain any combination of → scatterers, → absorbers, and → emitters.

→ radiative; → transfer.