radiatively

Radiatively is an adverb describing processes or interactions that involve radiation, typically electromagnetic radiation carried by photons. In physics, the term is used to qualify actions where energy is emitted, absorbed, or scattered as light. Radiative processes are contrasted with non-radiative mechanisms such as conduction, convection, or purely mechanical energy transfer.

In physics and astrophysics, radiative transfer describes how the intensity of radiation changes as it travels through matter due to emission, absorption, and scattering. This framework underpins the analysis of stellar and planetary atmospheres, interstellar and intergalactic gas, and other environments where light interacts with matter. Radiative cooling is a common outcome of such processes, as a gas emits photons and loses internal energy. Emission can occur through various atomic and molecular transitions, including electronic, vibrational, and rotational modes, producing characteristic spectral lines.

In astronomy, radiatively efficient and radiatively inefficient regimes describe how energy released by accreting matter is processed. An accretion flow that is radiatively efficient converts most gravitational potential energy into radiation, while a radiatively inefficient flow stores energy as heat, or transports it away by winds and jets. These distinctions influence the observed luminosity and spectrum of accreting systems such as black holes and neutron stars.

On the atomic scale, radiative transitions involve spontaneous emission and, in some contexts, stimulated emission, with radiative lifetimes determining how quickly excited states decay. Radiative processes are fundamental to spectroscopy and to understanding the energy balance of many physical systems.