| As a result of observations of pulsars with Chandra and XMM-Newton there have been many new X-ray pulsars detected. The high angular resolution, that Chandra and XMM- Newton offer, enabled us to resolve features not been resolved before. This has been particularly helpful in lifting the possible misinterpretation of the extended features. The spectral analysis of these sources can yield information about the emission mechanism and its location. Other than its initial heat content, the only source of energy available for an isolated pulsar is its spin-down energy. How much of this energy goes into high energy radiation is a crucial part of the problems underlying the energetics of the pulsar's X-ray emission. Pulsars emitting magnetospheric radiation (ie. rotation powered pulsars), as opposed to black-body emission coming from its surface, are excellent candidates for addressing this issue.;We have compiled the most up to date list of rotation powered X-ray pulsars. This list has 35 sources with 2 being uncertain. All pulsars on the list have, measured 2-10 keV X-ray fluxes together with a power-law index obtained from spectral fits. We have also compiled a list of all radio pulsars that have been observed in X-rays and not been detected. All thermally emitting pulsars, those which have a binary companion, and millisecond pulsars have not been included in either list. The pulsars in this list represent a wide range of ages, magnetic field strengths, and spin periods. Using this set of pulsars we found a linear relation between the X-ray luminosity (LX) and the rate of spin-down (E). By fitting a linear function to log LX vs. log E we found that the slope for young pulsars (Age < 1 Myr) is steeper than previous studies. Old pulsars (Age > 1 Myr) show a different behavior than young pulsars. They appear to be more efficient X-ray emitters and have steeper (softer) spectra, compared to the young pulsars. The variation from the trend lines is statistically significant but it can be explained by geometrical effects. |
