The Discovery of an Anomalous X-Ray Pulsar in the Supernova Remnant K[CLC]es 73[/CLC]

Abstract

We report the discovery of pulsed X-ray emission from the compactsource 1E 1841-045, using data obtained with the Advanced Satellitefor Cosmology and Astrophysics. The X-ray source is located in thecenter of the small-diameter supernova remnant (SNR) Kes 73 and isvery likely to be the compact stellar remnant of the supernova thatformed Kes 73. The X-rays are pulsed with a period of ~=11.8 s and asinusoidal modulation of roughly 30%. We interpret this modulation tobe the rotation period of an embedded neutron star, and as such itwould be the longest spin period for an isolated neutron star todate. This is especially remarkable since the surrounding SNR is veryyoung, ~2000 yr old. We suggest that the observed characteristics ofthis object are best understood within the framework of a neutronstar with an enormous dipolar magnetic field, B ~= 8 x 1014 G.