A Survey of Extended Radio Jets in Active Galactic Nuclei withChandraand theHubble Space Telescope: First Results

We present the first results from an X-ray and optical survey of a sample ofAGN radio jets with Chandra and HST. We focus here on the first six sourcesobserved at X-rays, in four of which a bright X-ray jet was detected for thefirst time. In three out of four cases optical emission from the jet is alsodetected in our HST images. We compare the X-ray morphology with the radio asderived from improved processing of archival VLA data and we construct spectralenergy distributions (SED) for the most conspicuous emission knots. In mostcases the SEDs, together with the similarity of the X-ray and radiomorphologies, favor an inverse Compton origin of the X-rays. The most likelyorigin of the seed photons is the Cosmic Microwave Background, implying thejets are still relativistic on kiloparsec scales. However, in the first knot ofthe PKS 1136-135 jet, X-rays are likely produced via the synchrotron process.In all four cases bulk Lorentz factors of a few are required. The radio maps ofthe two jets not detected by either Chandra or HST suggest that they are lessbeamed at large scales than the other four detected sources. Our resultsdemonstrate that, at the sensitivity and resolution of Chandra, X-ray emissionfrom extragalactic jets is common, yielding essential information on theirphysical properties.Comment: 32 pages; Fig 1-5 are in color. Accepted for publication in The Astrophysical Journa