The X-ray Properties of the Energetic Pulsar PSR J1838-0655: X-ray Properties of PSR J1838-0655

PSR J1838-0655 is an X-ray pulsar without significant radio detection. It is believed to be a rotationpowered X-ray pulsar and the X-ray position is consistent with coincides with an unidentified INTEGRAL source and roughly coincide with an extended TeV source, HESS J1837-069. Comparing with other known gamma-ray pulsars, the lack of radio detection of PSR J1838-0655 is similar to Geminga but no pulsation at gamma-ray bands have been confirmed yet. The VHE counterpart, HESS J1837-069might be associated with a SNR around PSR J1838-0655. In order to interpret the emission mechanism of PSR J1838-0655, we perform an joint spectral fit for the archival data of SUZAKU, CHANDRA, & RXTE. We find that the spectrum shows a broken power law with a spectral break at 6.5 keV. A line feature at 6.65 keV is also marginally detected in the spectra of XIS/Suzaku; this might originate from highly ionized Fe K(sub alpha) emission surrounding the pulsar. The physical properties (e.g. characteristic age approximately approximately 23 kyr, surface magnetic field approximately 1.9 x 10(exp 12) G and spin-down power approximately 5.5 x 10(exp 36) ergs/s) of PSR J1838-0655 is similar to a Vela-type pulsar but the high X-ray spin-down efficiency (approximately 0.9 %) and the existence of the X-ray spectral break indicate a possible connection to a Crab-like pulsar with the same emitting features. We discuss the possible radiation mechanisms from the observed spectral signatures of this unique pulsar and find that the emission from the magnetosphere of a greatly inclined rotator is the most favor interpretation for the conversion rate and the pulse profile at X-ray bands.