We present and interpret several new X-ray features of the X-ray pulsar PSR J1838–0655 .
The X-ray data are obtained from the archival data of CHANDRA , RXTE , and SUZAKU .
We combine all these X-ray data and fit the spectra with different models .
We find that the joint spectra are difficult to fit with a single power law ; a broken power-law model with a break at around 6.5 keV can improve the fit significantly .
The photon index changes from \Gamma = 1.0 ( below \mathrm { 6.5 ~ { } keV } ) to \Gamma = 1.5 ( above \mathrm { 6.5 ~ { } keV } ) ; this indicates a softer spectral behaviour at hard X-rays .
The X-ray flux at 2–20 keV is found to be \mathrm { 1.6 \times 10 ^ { -11 } ~ { } ergs~ { } cm ^ { -2 } ~ { } s ^ { -1 } } .
The conversion efficiency from the spin-down luminosity is \sim 0.9 % at 0.8–10 keV , which is much higher than that ( \sim 10 ^ { -3 } \% – 10 ^ { -4 } \% ) of the pulsars that show similar timing properties .
We discuss non-thermal radiation mechanisms for the observed high X-ray conversion efficiency and find that emission from the magnetosphere of a greatly inclined rotator is the most favorable interpretation for the conversion rate and the pulse profiles at X-ray bands .
A line feature close to \mathrm { 6.65 ~ { } keV } is also detected in the spectra of SUZAKU /XIS ; it might be the K _ { \alpha } emission of highly ionised Fe surrounding the pulsar .