The short time scale X-ray variability associated with the accretion disk around compact objects is complex and is vaguely understood. The study of the cross correlation function gives an insight into the energy dependent behavior of the variations and hence connected processes. Using high resolution RXTE data, we investigate the dynamical cross correlation function of an observation of a black hole source XTE J1550-564 in the steep power law state. The cross correlation between soft and hard X- ray energy bands revealed both correlated and anti-correlated delays (≤ ±15 s) on a correlation time scale of 50 s. It was noticed that the observed delays were similar to the delays between X-ray and optical/IR bands in other black hole and neutron star sources. We discuss the possible mechanisms/processes to explain the observed delays in the dynamical CCF.

ABSTRACT
1. INTRODUCTION
2. DATA REDUCTION AND ANALYSIS
3. DISCUSSION AND CONCLUSIONS
REFERENCES

• K. Sriram(Department of Astronomy, Osmania University)
• C. S. Choi(Korea Astronomy and Space Science Institute)
• A. R. Rao(Tata Institute of Fundamental Research)