INVERSE-COMPTON EMISSION & PHYSICAL CONDITIONS IN LOBES OF FRII RADIO GALAXIES

The magnetic field strength in the lobes of FRII radio galaxies and quasars is avital parameter for understanding their energetics and dynamics, since itcontrols the internal energy density and pressure. The only way of measuring itis by observing inverseCompton emission from the lobes, but existing detectionsare marginal and do not give a consistent value for the ratio of particle tomagnetic field energy density in a typical radio source. XMM.s sensitivity toextended structure makes it the instrument of choice for a systematic search forinverseCompton emission in typical FRII radio sources. We have selected a smallsample of such objects which will detect inverseCompton emission, confirm itsnature by determining its spectrum, and measure magnetic field strength to 10%. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]