XMM-Newton Observations of Radio Pulsars B0834+06 and B0826-34 and Implications for Pulsar Inner Accelerator

摘要

We report the X-ray observations of two radio pulsars with driftingsubpulses: B0834 + 06 and B0826 - 34 using \xmm\. PSR B0834 + 06 was detectedwith a total of 70 counts from the three EPIC instruments over 50 ks exposuretime. Its spectrum was best described as that of a blackbody (BB) withtemperature $T_s=(2.0^{+2.0}_{-0.9}) \times 10^6$ K and bolometric luminosityof $L_b=(8.6^{+14.2}_{-4.4}) \times 10^{28}$ erg s$^{-1}$. As it is typical inpulsars with BB thermal components in their X-ray spectra, the hot spot surfacearea is much smaller than that of the canonical polar cap, implying anon-dipolar surface magnetic field much stronger than the dipolar componentderived from the pulsar spin-down (in this case about 50 times smaller andstronger, respectively). The second pulsar PSR B0826 - 34 was not detected over50 ks exposure time, giving an upper limit for the bolometric luminosity $L_b\leq 1.4 \times 10^{29}$ erg s$^{-1}$. We use these data as well as the radioemission data concerned with drifting subpulses to test the Partially ScreenedGap (PSG) model of the inner accelerator in pulsars.