089063

Magnetars form a small group of isolated X-ray pulsars powered by the dissipation of their magnetic energy. The physical mechanism powering their activity is currently poorly understood. It is in particular debated whether the long-term evolution of their outbursts is due to the cooling of the stellar crust and/or the untwisting of complex magnetic field structures in the magnetosphere. We propose joint observations with NuSTAR and XMM-Newton of the latest discovered magnetar in outburst SGR 1830-0645 to map the thermal structures on its surface test the model predictions for magnetar outbursts and gain insights into the physics of magnetars. emission. [truncated! Please see actual data for full text]