Fig. 2: Temporal evolution of the geometry of XTE J1810–197.
From: A freely precessing magnetar following an X-ray outburst
The top and bottom panels show the magnetic inclination angle α and the impact parameter β, respectively. Assuming the model independent free-precession scenario (constant ζ across all epochs), the orange and blue points represent the measurements from the Jodrell 1.5 GHz and Effelsberg 6 GHz data, respectively. We take the 95% confidence levels on the one-dimensional marginalized posterior as the uncertainties for the α and β measurements. The dot-dash line at β = 0° represents the crossing of the line of sight over the magnetic pole where the gradient of the PA is predicted to change sign. The period of time when the second X-ray outburst occurred is marked yellow. The dashed and dotted lines delimit the 95% confidence levels on α and β for the model of crust–core coupling with relaxing ellipticity and the phenomenological model of wobble angle decay with relaxing ellipticity model, respectively.
