The extended hard X-ray emission from the vela plerion

Abstract

We present the results of a broad band (3-200 keV) spectral analysis of BeppoSAX and XMM-Newton observations of the Vela plerion. The hard X-ray (> 15 keV) emission is found to be extended over a region of 12′-15′ radius, corresponding to a size of about 1.0-1.3 pc for a source distance of 290 pc. A single power law does not give an acceptable fit while a broken power law or a log-parabolic law nicely fit the data. The former spectral model has the photon index Γ1 = 1.66 ± 0.01 for energies lower than the break value equal to 12.5 keV and the index Γ2 = 2.01 ± 0.05 up to about 200 keV. The total X-ray luminosity of the Vela plerion is Lx = 5.5 × 1033 erg s-1, which implies a conversion factor of the spin-down power of ∼10-3. © ESO 2005.