Echoes from an Irradiated Disc in GRO J1655-40
Abstract
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 10-20s. 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 14.6s +/- 1.4 and dispersion (i.e. the standard deviation of the distribution) of 10.5s +/- 1.9 at binary phase 0.4. Hence we identify the reprocessing region as the accretion disc rather than the mass donor star.
Cite
@article{arxiv.astro-ph/9806038,
title = {Echoes from an Irradiated Disc in GRO J1655-40},
author = {R. I. Hynes and K. O'Brien and Keith Horne and W. Chen and C. A. Haswell},
journal= {arXiv preprint arXiv:astro-ph/9806038},
year = {2009}
}
Comments
5 pages with 11 postscript figures included, uses mn.sty. Accepted for publication as MNRAS letter