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An Optical Precursor to the Recent X-ray Outburst of the Black Hole Binary GRO J1655-40

Jerome A. Orosz·Ronald A. Remillard·Charles D. Bailyn·Jeffrey E. McClintock
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Abstract

The All Sky Monitor on the Rossi X-ray Timing Explorer detected an X-ray (2-12 keV) outburst from the black hole binary GRO J1655-40 beginning near April 25, 1996. Optical photometry obtained April 20-24, 1996 shows a steady brightening of the source in B, V, R, and I beginning about six days before the start of the X-ray outburst. The onset of the optical brightening was earliest in I and latest in B. However, the rate of the optical brightening was fastest in B and slowest in I. The order of the increases in the different optical filters suggests that the event was an "outside-in" disturbance of the accretion disk. The substantial delay between the optical rise and the rise of the X-rays may provide indirect support for the advection-dominated accretion flow model of the inner regions of the accretion disk.

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Jerome A. Orosz, Ronald A. Remillard, Charles D. Bailyn, Jeffrey E. McClintock. 1997-01-15. An Optical Precursor to the Recent X-ray Outburst of the Black Hole Binary GRO J1655-40. https://doi.org/10.1086/310553

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