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Session 40 - Radiogalaxies & Jets.
Display session, Tuesday, January 14
Metropolitan Ballroom,

[40.05] Models of Superluminal Sources: Relativistic Hydrodynamics and Radiation Transfer

P. A. Hughes (U. Michigan), A. J. Mioduszewski (NRAO), G. C. Duncan (Bowling Green State U.)

We present a family of jet simulations performed with a recently constructed relativistic hydrodynamic code. In one case we modulate the inflow to emulate a `restarting' jet, and present the results of radiation transfer calculations that compute the synchrotron intensity allowing for Doppler shift and boost, and for time-delay effects. These are the first such VLBI map simulations to incorporate all relevant relativistic effects in a way that admits an extensive exploration of parameter space: the mapping used to estimate radiating particle density, the properties of the particle spectrum, and the angle of view.

Even without relativistic effects, because of integration along the line of sight, the intensity maps contain much less structure than is seen in slices of the underlying hydrodynamic variables; time delays further reduce the extent to which knots are visible in a disturbed flow. Nevertheless, propagating structures are still evident, and the adopted approach -- performing the hydrodynamics and radiation transfer as distinct steps, despite the demand imposed on computer resources because of the need to store the entire history of the hydrodynamic simulation -- readily admits using a variety of diagnostics that explore the relation between observable structures and the underlying flow. This approach will be critical for the interpretation of the next generation of VLBI maps.

For the components of sources such as 3C 345 to remain distinct, despite the very small viewing angle inferred from recent VLBI/P observations, their intrinsic separation must be many hundred jet radii. We present both hydrodynamic simulations and the associated radiation transfer calculations for such a flow.

Program listing for Tuesday