Session 5. Blazars
Display, Monday, November 6, 2000, 8:00am-6:00pm, Bora Bora Ballroom

## [5.05] Structure of the X-ray Emission from the Jet of 3C 273

H.L. Marshall, P.M. Ogle (MIT CSR), J. Drake, A. Fruscione, J. Grimes, D. Harris, R. Kraft, S.S. Murray, D. Pease, D. Schwartz, A. Siemiginowska, S. Vrtilek, B. Wargelin (SAO)

We present images from several observations of the quasar 3C 273 with the Chandra X-ray Observatory. The zeroth order images from two grating observations using the ACIS-S detector and two others from direct imaging observations are used to determine spectrum of the jet and these are combined with an HRC-I image to obtain a broad-band X-ray image. The jet has at several distinct features which were not resolved in previous observations. The first knot in the jet (A1) is very bright in X-rays. Its X-ray spectrum is well fitted with a power law with \alpha = 0.86 ±0.11. Combining this measurement with lower frequency data shows that a pure synchrotron model can fit the spectrum of this knot from 4 GHz to 5 keV (over nine decades in energy) with \alpha = 0.82 ±0.01, consistent with the X-ray spectral slope. Thus, we can only place a lower limit on the total power radiated by this knot of 7 \times 1043 erg/s; more power may be emitted in the \gamma-ray band. Knot A2 is also detected and is somewhat blended with knot B1; again, synchrotron emission may explain the X-ray emission. For these two knots, the X-ray flux dominates the emitted energy.

This work was funded in part by contract SAO SV1-61010 and NASA contract NAS8-39073.