The existence of radio pulsars having inferred magnetic fields in the magnetar regime suggests that possible transition objects could be found in the radio pulsar population .
The discovery of such an object would contribute greatly to our understanding of neutron star physics .
Here we report on unusual X-ray emission detected from the radio pulsar PSR J1119–6127 using XMM–Newton .
The pulsar has a characteristic age of 1,700 yrs and inferred surface dipole magnetic field strength of 4.1 \times 10 ^ { 13 } G. In the 0.5-2.0 keV range , the emission shows a single , narrow pulse with an unusually high pulsed fraction of \sim 70 % .
No pulsations are detected in the 2.0–10.0 keV range , where we derive an upper limit at the 99 % level for the pulsed fraction of 28 % .
The pulsed emission is well described by a thermal blackbody model with a high temperature of \sim 2.4 \times 10 ^ { 6 } K. While no unambiguous signature of magnetar-like emission has been found in high-magnetic-field radio pulsars , the X-ray characteristics of PSR J1119–6127 require alternate models from those of conventional thermal emission from neutron stars .
In addition , PSR J1119–6127 is now the radio pulsar with the smallest characteristic age from which thermal X-ray emission has been detected .

\PACS 97.60.Jd 95.85.Nv 97.60.Gb