The discovery of rapidly repetitive X-ray bursts from a new source in Scorpius

Abstract

Rapidly repetitive X-ray bursts have been observed from a new X-ray source in Scorpius. More than 2000 bursts were observed during the ^4 day continual SAS-3 observations of this source which we designated MXB 1730-335. The time interval between bursts varied from a minimum of ^6 s to a maximum of ^5 minutes. The energy in a given burst is approximately linearly proportional to the time interval to the next burst. The largest bursts observed last for ~60 s and represent an energy release of ^10 40 ergs for an assumed distance to the source of 10 kpc. The smallest bursts observed last only for a few seconds. We suggest that the bursts are caused by sporadic precipitations of plasma from a reservoir in the magnetosphere of a neutron star. The reservoir is replenished at a nearly constant rate by mass transferred from a binary companion.