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Line-profile variations due to adiabatic non-radial pulsations in rotating stars
IV. The effects of intrinsic profile variations on the IPS diagnostics
C. Schrijvers 1 and
J.H. Telting 2
Received 14 August 1998 / Accepted 20 October 1998
We calculate time series of Doppler-broadened line-profiles of rotating stars that exhibit non-radial pulsations. We investigate the variability of such line profiles for cases in which variations of the intrinsic line-profile cannot be neglected. To study the effects of atmospheric changes on the line-profile variability we include: (1) local changes of the surface brightness, (2) local changes in the equivalent width of the intrinsic line profile, and (3) a non-adiabatic phase lag between the radial pulsational displacement and the surface-temperature perturbations.
We parameterize these three effects to extend the study presented in Paper I . The variability is analyzed by means of amplitude and phase diagrams obtained from Fourier transforms at each point of the line profile. One of our findings is that an asymmetry in the distribution of amplitude across the line profile can be caused by non-adiabaticity of the contributing temperature variations.
We perform Monte-Carlo simulations to investigate the correlation between the phase diagrams and the and m values of modes, in cases with line-profile variability that is dominated by the variable atmospheric properties. The retrieval of turns out to be similarly successful as in Paper II , where the variability was dominated by the surface-velocity field. We also find that harmonic variability is specific for pulsational surface-velocity fields rather than for variations of the surface temperature.
Key words: line: profiles methods: data analysis stars: early-type stars: oscillations stars: rotation stars: variables: ffi sct
Correspondence to: firstname.lastname@example.org
Online publication: February 22, 1999