2004ApJ...614L..45H

We have developed a timing analysis method to determine the distances of variable Galactic X-ray sources based on the method advanced by Trümper and Schönfelder in 1973. The light curve of the halo produced by the scattering of X-rays off the interstellar dust is delayed and smeared. The differences between the power density spectra of the point source and the halo contains the information of X-ray source distance and dust distribution along the line of sight. We present the details of this method and demonstrate its validity for the future X-ray astronomy instruments by simulations.