We present preliminary results of a simultaneous X-ray/optical campaign of the prototypical LMXB Sco X-1 at 1-10 Hz time resolution. Lightcurves of the high excitation Bowen/HeII emission lines and a red continuum at lambda ~ 6000 Ang were obtained through narrow interference filters with ULTRACAM, and these were cross-correlated with simultaneous RXTE X-ray lightcurves. We find evidence for correlated variability, in particular when Sco X-1 enters the Flaring Branch. The Bowen/HeII lightcurves lag the X-ray lightcurves with a light travel time which is consistent with reprocessing in the companion star while the continuum lightcurves have shorter delays consistent with reprocessing in the accretion disc
@article{arxiv.astro-ph/0507066,
title = {Multiband Echo Tomography of Sco X-1},
author = {T. Muñoz-Darias and I. G. Martínez-Pais and J. Casares and T. R. Marsh and R. Cornelisse and D. Steeghs and V. S. Dhillon and P. A. Charles},
journal= {arXiv preprint arXiv:astro-ph/0507066},
year = {2009}
}
Comments
4 pages, 1 figure; contribution presented at COSPAR Colloquium "Spectra & Timing of Compact X-ray Binaries," January 17-20, 2005, Bombay, India. To be published in Advances in Space Research