Constraining the spin-down of the nearby isolated neutron star RX J2143.0+0654.
KAPLAN D.L. and VAN KERKWIJK M.H.
Abstract (from CDS):
Magnetic field estimates for nearby isolated neutron stars (INS) help to constrain both the characteristics of the population and the nature of their peculiar X-ray spectra. From a series of XMM -Newton observations of RX J2143.0+0654, we measure a spin-down rate of. While this does not allow a definitive measurement of the dipole magnetic field strength, fields of ≳1014 G such as those inferred from the presence of a spectral absorption feature at 0.75 keV are excluded. Instead, the field is most likely around 2x1013 G, very similar to those of other INS. We not only suggest that this similarity most likely reflects the influence of magnetic field decay on this population, but also discuss a more speculative possibility that it results from peculiar conditions on the neutron-star surface. We find no evidence for spectral variability above the ∼2% level. We confirm the presence of the 0.75 keV feature found earlier, and find tentative evidence for an additional absorption feature at 0.4 keV.