Abstract for Proposal 096346

Prompt XMM-Newton and NuSTAR follow-up of magnetar outbursts

Magnetars are neutron stars powered by their huge magnetic fields. They experience extended periods characterized by short X-ray bursts, large giant flares, and months-timescale X-ray outbursts. Recently, several standard pulsars have exhibited magnetar-like emission, and an FRB-like event was detected during a short X-ray burst. We propose a joint \XMM\ (85 ks) and {\it NuSTAR} (160 ks) ToO program to gain new insights into the physics driving magnetar outbursts. These observations might answer the underlying physics and the reach of the magnetar phenomenon. This program will be triggered for any object (known or new) undergoing a magnetar-like outburst during the AO24, particularly leveraging the Einstein Probe all-sky monitoring capabilities to detect new outbursts from their onset.



Details on Observing Strategy and Trigger Criteria
We will trigger this XMM+NuSTAR proposal on the discovery (Einstein Probe, Swift, Fermi-GBM or MAXI) of SGR-like bursts, an X-ray outburst (10 times re-brightening wrt ROSAT) or FRB-like radio bursts from a new (or known) pulsar/magnetar. We ask for a single XMM trigger within AO24 for a total exposure time of 80ks divided in: 1 - XMM observation of 30ks within about 10 days from the detection of the burst/outburst, plus a second observation of 50ks when the sources will be undetected (expected to be about 50-200 days after) in the EP-WXT monitoring (the PI is part of the EP core team). Quasi-simultaneous NuSTAR observations (60ks and 100ks) are required to follow the hard X-ray activation and decay during the outburst.