Max Planck Inst Extraterr Phys, D-85741 Garching, Germany
; CAS, Inst High Energy Phys, Lab Cosm Ray & High Energy Astophys, Beijing 100039, Peoples R China
Spatially resolved (typically 10') soft X-ray spectral analyses of the whole Vela supernova remnant (SNR) are presented. The X-ray data were obtained in the ROSAT all-sky survey (RASS). The spectra can be well represented by two-temperature Raymond-Smith thermal plasma models. The spatial distributions of the temperatures of the hot component show that most of the central and the southern parts of the remnant are significantly hotter (1.2 keV) than the northern half (0.5 keV). The temperatures of the cool component range from 0.09 keV to 0.25 keV and have a distribution similar to that of the hot component. The emission measure of the cool component dominates the X-ray emission. It is distributed like the observed brightness, bright in the north and east and it shows filamentary structure. The distribution of the hot component emission measure appears to be flatter and it is significantly different from the intensity map. The absorption column densities N-H range from 5 x 10(19) cm(-2) to 6 x 10(20) cm(-2). The distribution shows that a large region in the north-east and the entire south-west are strongly absorbed. These strong absorption regions probably correspond to shocked low density HI clouds. We show that the Vela pulsar X-ray jet corresponds to an enhanced thermal pressure region south of the Vela pulsar. Both the thermal pressure map and the 0.9-2.4 keV intensity map show that the X-ray jet is 40' longer than previously claimed. The total X-ray flux of the Vela SNR in the 0.1-2.5 keV band is about 1.3 x 10(-8) erg cm(-2) s(-1). It corresponds to a luminosity of 2.2 x 10(35) erg s(-1) for a distance of 250 pc.