Atomic Recombination Cooling

Class providing recombination cooling rate coefficients (in cm\(^3\) s\(^{-1}\)) for ions of given atomic number and ionization state at a specified electron temperature. When a free electron recombines radiatively with an ion it releases energy both in the emitted photon and in the kinetic energy difference; the cooling rate coefficient quantifies this energy loss from the gas per recombination event. Case A (all recombinations) and case B (excluding direct recombinations to the ground state) coefficients are supported, consistent with the corresponding radiative recombination rate classes.

Default implementation: atomicRecombinationRateRadiativeCoolingHummer

Methods

rate → double precision

Returns the recombination cooling rate coefficient in units of cm\(^3\) s\(^{-1}\).

  • integer , intent(in ) :: atomicNumber, ionizationState

  • double precision , intent(in ) :: temperature

  • type (enumerationRecombinationCaseType), intent(in ), optional :: level

atomicRecombinationRateRadiativeCoolingComputed

Atomic radiative cooling rates computed from the corresponding photoionization cross section using detailed balance (i.e. the Milne relation—see for example “Astrophysics of the Diffuse Universe” by Dopita & Sutherland, 2004, Springer Science & Business Media, section 5.3.3).

atomicRecombinationRateRadiativeCoolingFixed

Atomic radiative cooling rates which are a fixed multiple of the recombination rate, \(\beta = \gamma \alpha\) where \(\alpha\) is the corresponding radiative recombination coefficient and \(\gamma\) is a parameter.

Parameters

  • [gamma] (real; default 0.67d0) — The multiplicative factor, \(\gamma\), used to compute the cooling coefficient.

atomicRecombinationRateRadiativeCoolingHummer

Atomic radiative cooling rates based on the tabulated results of Hummer (1994) and Hummer and Storey (1998). For non-hydrogenic or helium-like ions an optional default of \(\beta = \gamma \alpha\) can be returned where \(\alpha\) is the corresponding radiative recombination coefficient and \(\gamma\) is a parameter.

(Default implementation)

Parameters

  • [gamma] (real; default 0.67d0) — The multiplicative factor, \(\gamma\), used to compute the cooling coefficient in cases of non-hydrogenic or helium-like ions.