Previously we have studied the jet of the quasar 3C 273 at optical and radio frequencies. In our first set of X-ray data with 17.2 ksec integration time obtained with the ROSAT HRI, the jet is easily visible extending out from the bright quasar core. The total number of counts in the jet lies in the range 200 to 300, depending on the details of the background model. This corresponds to an X-ray flux fv(2.9 × 1017 Hz) = 65 … 140 nJy (lower limit, synchrotron radiation α = −0.8 … upper limit, bremsstrahlung α = 0, NHI = 1.8 × 1020 cm−2), in good agreement with the value derived from the EINSTEIN observations.
The background model of the medium energy X-ray telescope of Insight-HXMT