Radio Sources and their Environments
As radio sources evolve they strongly
interact with their environment. We are investigating how this interaction
effects galaxy evolution in general as well as the feedback effect of the
radio source on its host galaxy and AGN.
showing the extended optical emission associated with 3CXXX. The
false-colour image is of an HST observation and the contours show the radio
One direct observational manifestation of this interaction is the existence
of extended regions of emission-line gas which show a clear spatial relationship
to the radio source itself. This extended emission shows evidence
of both shock excitation and excitation by the AGN itself.
evidence for radio-source induced star-formation may have been recently
detected at z ~ 1 in our HST imaging of at least one 6C radio
To investigate the comological evolution of this interaction we are working
on a comparison of our 3CR sample and a sample of 6C radio galaxies at
z~1 using HST imaging, UKIRT JHK imaging, WHT Isis spectroscopy as well
as radio studies. We are able to compare directly objects matched
in power but at different redshift as well as objects of different power
at the same redshift thus breaking the P-z degeneracy.
of a simulation showing the gas density as a two-jet radio source propagates
into a realistic cluster atmosphere which has a pre-existing cooling flow.
A video of this simulation is also available showing density
and temperature evolution.
We are modelling the interaction of the radio sources with their environments
using analytical and computational techniques. The aim is to obtain an
understanding of the effect of the effect of the radio source on the intracluster
gas and feedback processes on the AGN itself. Simulations and analytical
modelling of the passage of a radio source through a clumpy inhomogeneous
medium are being used to help understand our observational work on the
extended emission-line gas.
The 3D numerical hydrodynamic simulations are performed using the
code (a computational fluid dynamics code developed at the Laboratory for
Computational Astrophysics at the NCSA) and run on our local Beowulf
Last modified: 20/1/2002