出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present simultaneous high time resolution (1-10 Hz) X-ray and optical observations of the LMXBs Sco X-1 and 4U 1636-536. For Sco X-1 we find that the Bowen/HeII emission lags the X-ray light-curves with a light travel time of ∼ 11−16s which is consistent with reprocessing in the donor star. We also present the detection of three correlated X-ray/optical bursts in 4U 1636- 536. Our results obtained by subtracting the Continuum light-curve from the Bowen/HeII data provide evidence of orbital phase dependent echoes from the companion star. This work shows how bursters are probably the best candidates for applying this technique.
