X-ray study of the galactic SNR G65.3+5.7

G65.3+5.7 is a galactic supernova remnant with a diameter of 3.2 . An X-ray image covering for the first time the entire remnant was obtained in the ROSAT all-sky survey. In addition, 17 pointed observations with the ROSAT PSPC were performed to derive spectral information. The X-ray emission of G65.3+5.7 is thermal represented by two components differing in temperature, with the low temperature component of 0.2 keV dominating. The ambient matter density of0.019 cm-3 is fairly low. Adopting a distance of 1 kpc the Sedov age turns out to be27500 years involving an explosion energy of 0.2 ×1051 erg . The spectral analysis of the pointed observations indicate small spatial variations in photoelectric absorption and temperature with a slight increase towards the center. The radio pulsar PSR J1931+30 with a period of 582 ms is located within the boundaries of G65.3+5.7 offset by45' from the geometrical center of the remnant. With just this information an association of the pulsar with the remnant cannot be claimed. We note that the upper limit of the X-ray luminosity is Lx = 4.8 ×1031 × d1 erg /s for a distance d = 1 kpc comparable with the SNR distance (the dispersion of the pulsar radio signal suggests d3 kpc). The luminosities of the 65 ms pulsar PSR J0205+6449 associated with 3C58 and B0833-45 in the Vela SNR are in the same range given the uncertainty of d.