Monitoring cygnus X-1 with RXTE

Since 1997 we have monitored Cyg X-1 on a bi-weekly timescale with simultaneous X-ray and radio observations with RXTE and the Ryle telescope. We present results from this continuing campaign such as correlations between different timing parameters (X-ray time lag, X-ray coherence function, the rms-flux relation, etc.) and we show that the power spectrum of Cyg X-1 can be well described by the sum of four broad Lorentzian components. The behavior of these components follows the same correlations that were also seen in the Lorentzian decomposition of the power spectra of neutron stars.