Echoes from the companion star in Sco X-1
Astrophysics
2008-11-26 v1
Abstract
We present simultaneous X-ray (RXTE) and optical (ULTRACAM) narrow band (Bowen blend/HeII and nearby continuum) observations of Sco X-1 at 2-10 Hz time resolution. 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 companion star. The echo from the donor is detected at orbital phase ~0.5 when Sco X-1 is at the top of the Flaring Branch. Evidence of echoes is also seen at the bottom of the Flaring Branch but with time-lags of 5-10s which are consistent with reprocessing in an accretion disc with a radial temperature profile. We discuss the implication of our results for the orbital parameters of Sco X-1.
Cite
@article{arxiv.0705.4568,
title = {Echoes from the companion star in Sco X-1},
author = {T. Muñoz-Darias and I. G. Martinez-Pais and J. Casares and V. S. Dhillon and T. R. Marsh and R. Cornelisse and D. Steeghs and P. A. Charles},
journal= {arXiv preprint arXiv:0705.4568},
year = {2008}
}
Comments
Accepted for publication in MNRAS