Dr Joanna Berteaud

Magnetars are  young, isolated neutron stars with long spin periods and large spin-down rates, implying large surface dipole magnetic field strengths. They are usually observed as bright and pulsating X-ray sources with luminosities exceeding their rotational energy losses. Hence, unlike the less-magnetic rotation-powered pulsars, magnetars are believed to be powered through the decay of their large inferred magnetic fields. The X-ray timing of 1E2259+586, monitored since 1996, shows abrupt spin-downs and spin-ups called glitches and anti-glitches. These glitches can be radiatively quiet, suggesting that these phenomena originate in the neutron star interior, and that their triggering mechanisms do not necessarily have to be connected to the magnetosphere. In this talk, I will present our recent analysis of NICER data of 1E2259+586 and other magnetars, collected between 2018 and 2025, and report on the discovery of new timing discontinuities.