The Dynamic Age of Centaurus A

Understand

In this paper I present dynamic models of the radio source Centaurus A, and critique possible models of in situ particle reacceleration (ISR) within the radio lobes.

• The radio and gamma-ray data require neither homogeneous plasma nor quasi-equipartition between plasma and magnetic field; inhomogeneous models containing both high-field and low-field regions are equally likely.
• Cen A cannot be as young as the radiative lifetimes of its relativistic electrons, which range from a few to several tens of Myr.
• Two classes of dynamic models -- flow driven and magnetically driven -- are consistent with current observations; each requires Cen A to be on the order of a Gyr old.