XMM-NEWTON X-RAY DETECTION OF THE HIGH-MAGNETIC-FIELD RADIO PULSAR PSR B1916+14

Using observations made with the XMM-Newton Observatory, we report the first X-ray detection of the high-magnetic-field radio pulsar PSR B1916+14. We show that the X-ray spectrum of the pulsar can be well fitted with an absorbed blackbody with temperature in the range of 0.08-0.23 keV, or a neutronstar hydrogen atmosphere model with best-fit effective temperature of similar to 0.10 keV, higher than expected from fast cooling models. The origin of the likely thermal emission is not well constrained by our short observation and is consistent with initial cooling or return-current heating. We found no pulsations in these data and set a 1 sigma upper limit on the pulsed fraction in the 0.1-2 keV band of similar to 0.7. Implications of these results for our understanding of the different observational properties of isolated neutron stars are discussed.