“Soft X-ray transient” outbursts which are not soft

✍ Scribed by C. Brocksopp; R.M. Bandyopadhyay; R.P. Fender

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 589 KB
• Volume: 9
• Category: Article
• ISSN: 1384-1076
• DOI: 10.1016/j.newast.2003.11.002

✦ Synopsis

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