DOPPLER TOMOGRAPHY AND S-WAVE ANALYSIS OF CIRCUMSTELLAR GAS IN BETA-PERSEI

The H alpha difference profiles of beta Per obtained from 1976 to 1977 have been analyzed in several ways to study the gas flows in the bina ry. These difference profiles were obtained by removing the combined s tellar photospheric absorption contribution from the observed profiles to enhance the weak emission from circumstellar gas. The difference p rofiles display strong narrow single-peaked emission and broader doubl e-peaked emission. The line strengths peaked near phase 0.7 for the bl ueshifted emission and near phase 0.2 for the redshifted emission. The se maxima occur at phases where our line of sight would pass through t he gas stream or an accretion region located between the stars. The or bital variations of the radial velocities of the single- and double-pe aked emission followed S-waves. The source of the single-peaked emissi on was found at velocities close to the L(1) point on the side of the secondary star in the direction of the gas stream trajectory, as if as sociated with the gas stream. However, the source of the double-peaked emission was found at velocities almost halfway between that of the s tars, in the direction away from the gas stream. The double-peaked nat ure of these profiles imply that they arise from an accretion region s urrounding the primary star, with the most intense, concentrated part between the stars. Reconstructed Doppler images of the binary from Dop pler tomography are consistent with the S-wave analysis and show that there are several sources of emission (from strongest to weakest): a g as stream, a localized region, and an unstable asymmetric accretion an nulus. The gas stream extends from the L(1) point to the impact site o n the stellar surface, but it tapers sharply about halfway along its p ath as if blocked by material around the primary. Finally, the weakest source arose from the region around the secondary star, so chromosphe ric emission from the magnetically active subgiant secondary has been detected in the Doppler image.