HYDROGEN INFRARED RECOMBINATION LINE-PROFILES IN BE-STAR WINDS

We present theoretical Hydrogen infra-red recombination line profiles from flattened, rotating and slowly expanding discs around Be stars. The IR lines show a double-peaked structure characteristic of rotating discs, but with a V/R ratio which is reversed compared to the V/R ratio of the H-alpha line. This effect can be explained in terms of the formation region of the lines in combination with continuum optical depth effects that affect the IR lines. Our calculations demonstrate that some emission lines from rotating and expanding discs can also show a violet peak that is stronger than the red peak (V > R). Infra-red recombination line profiles are sensitive probes of the velocity and density structure of their region of formation.