Nebular free-bound continuum
= Nebular free-bound continuum
A <nebular free-bound continuum> is emitted when a free <electron> is captured into a bound atomic level and its excess <energy> leaves as a <photon>. The threshold energies produce <recombination> edges such as the Balmer discontinuity. Its spectrum depends on <electron> <temperature>, ionic abundances, capture cross-sections and emission measure; it is distinct from bound-bound <recombination> lines and free-free bremsstrahlung.