Bibcode
Shahbaz, T.; Dhillon, V. S.; Marsh, T. R.; Casares, J.; Zurita, C.; Charles, P. A.; Haswell, C. A.; Hynes, R. I.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 362, Issue 3, pp. 975-982.
Fecha de publicación:
9
2005
Número de citas
22
Número de citas referidas
21
Descripción
We present high time-resolution multicolour observations of the
quiescent soft X-ray transient XTE J1118+480 obtained with ULTRACAM.
Superimposed on the double-humped continuum g'- and i'-band light curves
are rapid flare events which typically last a few minutes. The power
density spectrum of the light curves can be described by a broken
power-law model with a break frequency at ~2 mHz or a power-law model
plus a broad quasi-periodic oscillation at ~2 mHz. In the context of the
cellular automaton we estimate the size of the quiescent
advection-dominated accretion flow (ADAF) region to be ~104
Schwarzschild radii, similar to that observed in other quiescent black
hole X-ray transients, suggesting the same underlying physics. The
similarities between the low/hard and quiescent-state power density
spectrum suggest a similar origin for the optical and X-ray variability,
most likely from regions at or near the ADAF.