Radiative losses in solar and stellar coronae

For {kappa}-distributions, the radiative-loss functions are in general lesser than for Maxwellian distribution, with few exceptions caused by the behavior of Fe. The peaks of the radiative-loss functions are in general flatter. The situation is opposite for n-distributions, for which the radiative-loss functions have higher and narrower peaks.

Local minima and maxima of the radiative-loss functions may also be shifted. The contribution from bremsstrahlung change only by few percent except the extreme nonthermal case of {kappa}=2. Stability analysis reveals that the X-ray loops are stable against the radiatively-driven thermal instability.