Temporal and spectral variability in luminous X-ray binaries

A variety of timing analyses have been applied to data from recent Ginga observations of Galactic Black Hole Candidates (BHC) and Low Mass X-ray Binaries (LMXB) to probe spectral and temporal variability.; 1. A cross spectral analysis of Cyg X-1 and GX 339-4. The cross spectral coherence function is used to study temporal correlations between hard and soft photons from Cyg X-1 and GX 339-4. A technique is developed to correct for counting noise and applied to Cyg X-1 to estimate the extent of the Compton scattering region. The region size is found to be of order.014 light seconds.; 2. Correlation between QPO and LFN in GX 5-1. Statistical tests are developed to probe correlations between the QPO and LFN in GX 5-1 on the horizontal branch. At long times scales, QPO and LFN amplitudes are found to be correlated, but below 8 seconds the correlation disappears. Tests are callibrated through extensive simulations. We place severe constraints on the Beat Frequency model.; 3. X-ray variability of Sco X-1 during a multiwavelength campaign. We present results of a March 1989 Ginga observation of Sco X-1 as part of a simultaneous worldwide multiwavelength campaign. We see both normal and flaring branch QPO. To test Z-diagram position as a state variable, we probe for correlations between velocity along the diagram and measurable quantities. Finally, we perform a search for coherent oscillation and find none, with an upper limit of 0.2%.; 4. Search for coherent oscillations in Low Mass X-ray Binaries. Using Ginga and HEAO-1 data, we have performed the most sensitive search to date for coherent oscillations in LMXB. We describe a technique to compensate for Doppler smearing by source orbital motion with a single correction parameter, and obtain modulation depth limits for Sco X-1, GX 5-1, Cyg X-2, GX 340 + 0, GX 9 + 1 and 1820-30.