Research Information System
ASTRONOMY & ASTROPHYSICS, vol.447, no.2, pp.545-551, 2006 (SCI-Expanded)
We present broad band power spectra of variations of SS433 in radio, optical and X-ray spectral bands. We show that at frequencies lower than 10(-5) Hz the Source demonstrates the same variability pattern in all these bands. The broad band power spectrum call be fitted by one power law down to frequencies similar to 10(-7) Hz with flattening afterwards. Such a flattening means that on time scales longer than similar to 10(7) s the source variability becomes Uncorrelated. This naturally leads to the appearance of quasi-poissonian flares in the source light curve, which have been regularly observed in radio and optical spectral bands. The radio flux power spectrum appears to have a second break at Fourier frequencies similar to 10(-5) Hz which can be Caused by the smearing of the intrinsic radio variability on timescale of the light-crossing time of the radio emitting region. We find a correlation of the radio and optical fluxes of SS433 and the radio flux is delayed by about similar to 2 days with respect to the optical one. Power spectra of optical and X-ray variabilities continue with the same power law from 10(-7) Hz up to similar to 0.01-0.05 Hz. The broad band power spectrum of SS433 can be interpreted in terms of self-similar accretion rate modulations in the accretion disk proposed by Lyubarskii (1997, MNRAS, 292, 679) and elaborated by Churazov et al. (2001, MNRAS, 321, 759). We discuss a viscous time-scale in the accretion disk of SS433 with reference to the observed broad band power spectrum.