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Super-orbital variability in Cygnus X-1. ISSI, Bern, Switzerland March 3-7, 2008. J. Poutanen, A. Zdziarski, A. Ibragimov MNRAS, submitted. Accretion via Roche lobe and focused wind. Stream trajectory and disk formation for the case of equal masses.
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Super-orbital variability in Cygnus X-1 ISSI, Bern, Switzerland March 3-7, 2008 J. Poutanen, A. Zdziarski, A. Ibragimov MNRAS, submitted
Accretion via Roche lobe and focused wind • Stream trajectory and disk formation for the case of equal masses. • Coriolis force shifts the stream from the line connecting the stars.
Superorbital variability Radio X-rays
(c) A view from the top bulge b disc supergiant =0.5 =0
(a) A view along the orbital plane, =0 observer i bulge supergiant black hole disc =0.5 =0
(b) A view along the orbital plane, =0.5 observer disc supergiant black hole bulge =0.5 =0
Model • Bulge • Wind • Parameters: inclination i=40 deg • Precession angle Precession angle Optical depths: bulge b,0 , wind w,0 Bulge azimuth b
Model • Emissivity profile of the accretion disk • For the jet/ outflow
Conclusions • Discovery of orbital modulation strength on superorbital phase of Cyg X-1 • Effect can be explained by the bulge displaced from the line connecting the stars by 25 deg. • Distribution of dips is consistent with the model • Beat-frequencies should be observed, with the stronger lower one.