1. Super-orbital variability
in Cygnus X-1
ISSI, Bern, Switzerland
March 3-7, 2008
J. Poutanen, A. Zdziarski, A. Ibragimov
MNRAS, submitted

2. 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.

3. Superorbital variability
Radio
X-rays

4. Dips distribution

5. Orbital profiles as a function of superorbital phase

6. (c) A view from the top
bulge
 b
disc
supergiant
 =0.5
 =0

7. i    =0.5  =0 observer (a) A view along the orbital plane,  =0
bulge 
supergiant 
black hole
disc
 =0.5
 =0

8.  =0.5  =0 observer (b) A view along the orbital plane,  =0.5 disc
supergiant
black hole
bulge
 =0.5
 =0

9. Model Wind Parameters: inclination i=40 deg Precession angle  Bulge
Optical depths:
bulge b,0 , wind w,0
Bulge azimuth b

10. Model
Emissivity profile of the accretion disk
For the jet/ outflow

11. Orbital profiles as a function of superorbital phase

12. Results

13. PDS of the model flux

14. 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.

15. Log-normal flux distribution