Michael Herman (Fall 2003, Spring 2004, Summer 2004): Modeling Helical
Jets
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The jetted outflows from active galaxies are subject to a variety of
instabilities that can radically change their kinematics and
appearance. Since it is believed that jets are aligned with the spin
axis of the central black hole that powers them, any slight precession
of this axis can set up a driven helical instability, in which the
outflow follows a spiral,helical pattern. A simple model of a conical
helix has been developed to approximate this pattern, and fit to data
on the active galaxy CTA 102 to constrain the speed and orientation of
its jet, as well as its path in three dimensions. The model will also
be applied to several other active galaxies to investigate where deceleration of the
jet plasma occurs.