Katherine Blundell OBE

Abstract:

We are investigating possible triggering scenarios which may give rise to powerful jetted active galaxies such as classical double radio galaxies. Important clues come from studying those objects which have most recently been triggered. The newly discovered 'Youth-Redshift Degeneracy' for classical double radio galaxies means that the highest redshift objects in a flux-limited survey will be observed to be significantly younger (more recently triggered) than the more nearby objects. We are pursuing this investigation with a new sample specially filtered to favour the detection of high-redshift radio galaxies. We will present some preliminary results of a near-IR imaging campaign using the UIFTI on the UKIRT.

Abstract:

We review several ways in which X-ray observations are helping to tie down the physical parameters in radio lobes and jets, resolving most of the notorious uncertainties which afflict estimates from synchrotron emission alone. Together, the new results imply that the energy density of jet plasma is dominated by particles which do not contribute to the observed radiation, such as relativistic protons or mildly relativistic electrons, These components have long been hypothesised but their implications have often been ignored. Their presence substantially increases estimates of the energy budget for jet activity, and implies that jets may be an important heat source for the intracluster gas.

Abstract:

High resolution X-ray and low frequency radio imaging now allow us to examine in detail the interaction and physical properties of the radio source 3C84 and the surrounding thermal gas. The radiative and dynamical properties of the inner X-ray holes, which coincide with the radio lobes, indicate that the ratio of the energy factor k and filling factor f is in the range 180

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