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Multiband Echo Tomography of Sco X-1

T. Muñoz-Darias·I. G. Martínez-Pais·J. Casares·T. R. Marsh·R. Cornelisse·D. Steeghs·V. S. Dhillon·P. A. Charles
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Abstract

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

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T. Muñoz-Darias, I. G. Martínez-Pais, J. Casares, T. R. Marsh, R. Cornelisse, D. Steeghs, V. S. Dhillon, P. A. Charles. 2005-07-04. Multiband Echo Tomography of Sco X-1. https://doi.org/10.1016/j.asr.2005.10.056

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