Echoes from an Irradiated Disc in GRO J 1655 – 40
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چکیده
We demonstrate correlated rapid variability between the optical/UV and X-ray emission for the first time in a soft X-ray transient, GRO J1655–40: HST light curves show similar features to those seen by RXTE, but with mean delay of 10–20 s. We interpret the correlations as due to reprocessing of X-rays into optical and UV emission, with a delay due to finite light travel time, and thus perform echo mapping of the system. The time-delay distribution has a mean of 14.6 ± 1.4 s and dispersion (i.e. the standard deviation of the distribution) of 10.5 ± 1.9 s at binary phase 0.4. Hence we identify the reprocessing region as the accretion disc rather than the mass donor star.
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تاریخ انتشار 1998