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Continuum Emission

Diffuse continuum radiation is emitted by three processes: thermal bremsstrahlung, radiative recombination, and two-photon decays of metastable levels. The thermal bremsstrahlung emissivity is given by [Osterbrock 1974]:


\begin{displaymath}j_\varepsilon={{1}\over{4\pi}}n_zn_e{{32Z^2e^4h}\over{3m^2c^3...
...0}\over{3kT}}\right)^{1/2}e^{-h\nu/kT}g_{ff}(T,Z,r) \eqno{(9)} \end{displaymath}

where T is the electron temperature, $n_e$ is the electron abundance, Z is the charge on the most abundant ion, $n_z$ is the abundance of that ion, and $g_{ff}$ is a Gaunt factor ([Karzas and Latter, 1966]). For two photon decays, we adopt the distribution ([Tucker and Koren 1971]):


\begin{displaymath}H\left({{\varepsilon}\over{\varepsilon_0}}\right)=
12\left({{...
...\left(1-{{\varepsilon}\over{\varepsilon_0}}\right) \eqno{(10)} \end{displaymath}

where $\varepsilon_0$ is the excitation energy.



Tim Kallman 2014-04-04