We report on the detection of PSR 1706-44 in two ROSAT-PSPC observations. The recorded source counts are unpulsed with a $2sigma$ pulsed fraction upper limit of 18%. Spectral analysis did not distinguish between black-body and power law models; however, we argue that the lack of pulsations and the similarity in the pulsars spin parameters to those of the Vela pulsar favour a power law model $dN/dEpropto E^{-2.4pm 0.6}$ and indicate synchrotron emission from a pulsar-powered nebula as the origin of the detected X-radiation. The X-ray flux derived for the power law model is f_x=3.2^{+6.5}_{-1.8} x E-12 erg/ s/ cm^2 within the 0.1-2.4 keV energy range. An upper limit for the neutron stars surface temperature is put at Log T_s^infty sim 6.03 K for a neutron star with a medium stiff equation of state (FP-model with M=1.4 Mo, R=10.85 km). Slightly different values for $T_s^infty$ are computed for the various neutron star models available in the literature, reflecting the difference in the equation of state. No soft X-ray emission is detected from the supernova remnant G343.1-2.3, proposed to be associated with PSR 1706-44.
تحميل البحث