Document Type
Article
Publication Date
9-21-2005
Abstract
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 ∼10 4 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. © 2005 RAS.
Publication Source (Journal or Book title)
Monthly Notices of the Royal Astronomical Society
First Page
975
Last Page
982
Recommended Citation
Shahbaz, T., Dhillon, V., Marsh, T., Casares, J., Zurita, C., Charles, P., Haswell, C., & Hynes, R. (2005). ULTRACAM observations of the black hole X-ray transient XTE J1118+480 in quiescence. Monthly Notices of the Royal Astronomical Society, 362 (3), 975-982. https://doi.org/10.1111/j.1365-2966.2005.09361.x