X - ray Emission Properties of the Old Pulsar PSR B 2224 + 65

Using archival Chandra data we studied the X-ray emission properties of PSR B2224+65 and its environment. Albeit limited by photon statistics the spectral analysis suggests that the bulk of the emission from PSR B2224+65 is non-thermal. Fitting a power-law to the observed energy spectrum yields a photon index of Γ = 1.58 +0.43 −0.33. The possible origin of the non-thermal pulsar emission is discussed in the context of the outer-gap model. We did not find any evidence for a compact nebula around PSR B2224+65 though the Chandra data reveal the existence of an extended feature which appears to be associated with PSR B2224+65. It extends from the pulsar position about 2 arcmin to the northwest. Its orientation deviates by ∼ 118 • from the pulsar's proper motion direction. Investigating its energy spectrum shows that the emission of this extended feature is much harder than that of the pulsar itself and is non-thermal in nature.