Inference of hot star density stream properties from data on rotationally recurrent DACs

Abstract

The information content of data on rotationally periodic recurrent discrete absorption components (DACs) in hot star wind emission lines is discussed. The data comprise optical depths tau(w,φ) as a function of dimensionless Doppler velocity w=(Deltalambda/lambda0)(c/v&infy) and of time expressed in terms of stellar rotation angle φ. This is used to study the spatial distributions of density, radial and rotational velocities, and ionisation structures of the corotating wind streams to which recurrent DACs are conventionally attributed