We present the latest results from a multi-epoch timing and spectral study of the Transient Anomalous X-ray Pulsar XTE J1810–197 .
We have acquired seven observations of this pulsar with the Newton X-ray Multi-mirror Mission ( XMM-Newton ) over the course of two and a half years , to follow the spectral evolution as the source fades from outburst .
The spectrum is arguably best characterized by a two-temperature blackbody whose luminosities are decreasing exponentially with \tau _ { 1 } = 870 d and \tau _ { 2 } = 280 d , respectively .
The temperatures of these components are currently cooling at a rate of 22 % per year from a nearly constant value recorded at earlier epochs of kT _ { 1 } = 0.25 keV and kT _ { 2 } = 0.67 keV , respectively .
The new data show that the temperature T _ { 1 } and luminosity of that component have nearly returned to their historic quiescent levels and that its pulsed fraction , which has steadily decreased with time , is now consistent with the previous lack of detected pulsations in quiescence .
We also summarize the detections of radio emission from XTE J1810–197 , the first confirmed for any AXP .
We consider possible models for the emission geometry and mechanisms of XTE J1810–197 . \PACS 95.85.-e 95.85.Nv 97.60.Jd 97.60.Gb 95.75