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The Hard Truth about Some "Soft" X-ray Transients

R. M. Bandyopadhyay·C. Brocksopp·R. P. Fender
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Abstract

We have accumulated multiwavelength lightcurves for eight black hole X-ray binaries which have been observed to enter a supposed ``soft X-ray transient'' outburst, but which in fact remained in the low/hard state throughout the outburst. Comparison of the lightcurve morphologies, spectral behaviour, properties of the QPOs and the radio jet provides the first study of such objects as a subclass of X-ray transients (XRTs). However, rather than assuming that these hard state XRTs are different from ``canonical'' soft XRTs, we prefer to consider the possibility that a new analysis of both soft and hard state XRTs in a spectral context will provide a model capable of explaining the outburst mechanisms for the majority of black hole X-ray binaries.

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R. M. Bandyopadhyay, C. Brocksopp, R. P. Fender. 2002-07-18. The Hard Truth about Some "Soft" X-ray Transients. https://arxiv.org/abs/astro-ph/0207386

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