Abstract for Proposal 084545

XMM-NEWTON OBSERVATION OF HIGHLY STRUCTURED FLARING IN THE BURSTING PULSAR

The Bursting Pulsar (GRO J1744-28) is a neutron star low-mass X-Ray binary. In addition to showing Type II X-Ray bursts during outburst, at lower luminosities the source displays highly structured X-ray flaring remarkably similar to variability seen in the enigmatic black hole binary GRS 1915+105. The mechanism behind this variability is poorly understood, but believed to be related to the viscous instabilities which also give rise to Type II bursts. As such, the Bursting Pulsar is an excellent case study to study the relationship between these two behaviours. We propose two joint XMM-Newton and NuStar ToO observations totalling 80 ksec, separated by 15 days to capture both GRS 1915-like behaviour and the bursting behaviour which immediately precedes it.

Details on Observing Strategy and Trigger Criteria
We will trigger our first observation during an outburst of the Bursting Pulsar 40 days after the source s X-ray flux falls below 10% Eddington, or before that time if Mesobursts (see text of proposal) are seen with Swift/XRT.