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R. P. Kraft, W. R. Forman, C. Jones, S.S. Murray (Harvard-Smithsonian CfA)
We present results of the analysis of two 35 ks {\em Chandra}/ACIS-I observations of the X-ray jet in the nearby (3.5 Mpc) radio galaxy Centaurus~A. We find that that jet consists of at least 31 discrete, compact knots of enhanced emission embedded within continuous diffuse emission extending from within ~ 50 pc of the active nucleus to more than 4 kpc from the nucleus into the NE radio lobe. Previous Einstein and ROSAT observations noted morphological similarities between the X-ray and radio emission of the inner jet region. We find small but significant differences at the arcsecond level making it unlikely that a single population of ultra-relativistic electrons is responsible for the emission from the radio to the X-ray band. The X-ray spectra of various regions of the jet is well described by an absorbed power law model with photon indices between 1.9 and 2.4. While statistically we cannot rule out thin plasma models, there is no direct evidence for any spectral lines. We conclude that the X-ray emission is due to synchrotron emission from ultra-relativistic electrons, and the knots are the sites of shocks where the electrons are re-energized. The radio and X-ray misalignments are likely due to particle aging and diffusion, similar to what has been seen in radio/optical observations of M87. We speculate that these misalignments may be a common feature of extragalactic jets.