Properties of X-ray bursts from the X-ray transient 1608-522

The recurrent X-ray transient 1608-522 was observed from the X-ray astronomy satellite Hakucho through the high- and low-luminosity states of its persistent flux. 1608-522 is identified to be a burst source from which 22 X-ray bursts were recorded. The burst peak intensity is found to fluctuate by a factor as large as 7. 1608-522 exhibited two distinctly different burst modes with respect to the burst profile and the peak luminosity distribution. The burst mode seems to have changed in correlation with the persistent flux, whereas the burst frequency as well as the time-averaged burst luminosity were essentially constant despite a large change in the persistent flux.