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Session 11 - QSOs and Radio Galaxies.
Display session, Monday, June 08
We present first results from simulations of relativistic electron transport and shock acceleration in time-dependent, multi-dimensional, magnetohydrodynamic, jet flows. These preliminary calculations are based on light, axis-symmetric jets carrying helical magnetic fields. The simulations are done using a new scheme designed for the moderate electron energies associated with radio synchrotron emission in radio galaxies. This enables us to follow the electron population and its spectral characteristics. We use these results to compute the local sychrotron emissivity and spectrum.
The simulations demonstrate that the properties and patterns of the relativistic populations and emissions are fundamentally influenced by the inherently unsteady behavior of jet flows. In particular, since the terminal shock is neither steady nor plane, relativistic electrons accelerated there exhibit a range of properties, both spatially and temporally within the jet terminal hot spot and the back-flow cocoon. Even without radiative cooling the electrons exhibit a range of spectral indices, even showing a tendency for the spectra to steepen with increasing distance from the hot spot. That particular feature comes from contributions by electrons accelerated by or passing only through weak, oblique portions of the jet terminal shock.
This work is supported in part by the National Science Foundation and the Minnesota Supercomputing Institute.
Program listing for Monday