The continuum re-processing efficiency of Be-star circumstellar discs

We have calculated the total flux emitted in H alpha, P alpha and Br alpha by the circumstellar envelope of both an early Be star, gamma Cas, and a late Be star, 1 Delphini, assuming the central star is the only source of energy input into the circumstellar envelope. These estimates are based on the Be-star models of Millar & Marlborough which have self-consistent temperature distributions determined by equating the local rates of energy gain and energy loss in the envelopes. We find that an additional source of ionizing photons, as argued by Apparao, is not necessary to account for the observed emission.