Echoes from the companion star in Sco X-1
Muñoz-Darias, T., Martinez-Pais, I. G., Casares, J., Dhillon, V. S., Marsh, T. R., Cornelisse, R., Steeghs, D. and Charles, P. A. (2007) Echoes from the companion star in Sco X-1. Monthly Notices of the Royal Astronomical Society, Vol.379 (No.4). pp. 1637-1646. doi:10.1111/j.1365-2966.2007.12045.x
WRAP_Steeghs_Companion_star_ 0705.4568v1.pdf - Accepted Version
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Official URL: http://dx.doi.org/10.1111/j.1365-2966.2007.12045.x
We present simultaneous X-ray (RXTE) and optical (ULTRACAM) narrow-band ( Bowen blend/He II and nearby continuum) observations of Sco X-1 at 2-10 Hz time resolution. We find that the Bowen/He II emission lags the X-ray light curves with a light traveltime of similar to 11-16 s which is consistent with reprocessing in the companion star. The echo from the donor is detected at orbital phase similar to 0.5 when Sco X-1 is at the top of the flaring branch (FB). Evidence of echoes is also seen at the bottom of the FB but with time-lags of 5-10 s 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.
Q Science > QB Astronomy
Faculty of Science > Physics
X-ray binaries
21 August 2007 Published
Particle Physics and Astronomy Research Council (Great Britain) (PPARC), Spain. Ministerio de Ciencia e Innovación (MICINN), Particle Physics and Astronomy Research Council (Great Britain) (PPARC), Smithsonian Astrophysical Observatory, United States. National Aeronautics and Space Administration (NASA)
PP/D002370/1 (PPARC), AYA2002-03570 (MICINN), NNG04G014G (NASA)
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