Structure of the X-Ray Emission from the Jet of 3C 273

Abstract

We present images from four Chandra observations of the quasar 3C 273. The zeroth order images from two grating observations using the AXAF CCD Imaging Spectrometer (ACIS-S) detector are used to examine the structure and spectrum of the jet. The jet has at least four distinct features which are not resolved in previous observations. Using jet feature nomenclature based on HST observations, we find that knot Al is very bright in X-rays. We have measured the X-ray spectrum of this X-ray knot for the first time, obtaining a photon index of 1.36 +/- 0.11 and a flux density of 37 +/- 4 nJy at 1 keV. Combining this measurement with lower frequency data shows that a pure synchrotron model can fit the spectrum of knot Al from 4 GHz to 5 keV (over nine decades in energy) without a change of spectral slope. Knot A2 is also detected and is somewhat blended with knot B1 but synchrotron emission is not likely to explain the X-ray emission due to the spectral turnover observed in the optical-UV band. No other knots are clearly detected but there is an indication of weak emission from the eastern portion of knot H3. near the head, which is radio-bright. There is diffuse flux which extends from 14 arcsec to 20 arcsec which shows curvature that is comparable to the optical flux found by Bahcall, et al.