Program: GN-2008A-Q-102

Title:How much energy is input into the IGM by AGN?
PI:Katherine Blundell
Co-I(s): Andy Fabian, Mary Erlund, Paul Hirst

Abstract

The overall goal for these observations is to understand how much energy is input into the IGM from radio jets: this depends on the *minimum* energy to which the power-law distribution of relativistic particles is accelerated in the hotspots, which for decades has been uncertain to within three orders of magnitude. Indeed, it was impossible for this minimum energy to be determined while studies of giant radio galaxies were made solely at radio wavelengths. In the Chandra and XMM era, dramatic steps forward have been made by the revealing of X-ray emission from inverse Compton scattering of CMB photons (ICCMB) to keV energies: this is important because it traces the presence of relativistic particles with Lorentz factors of 10^3. We propose to make 2.2-micron images (with NIRI) & 450-nm images (with GMOS) of the hotspots in two examples of giant (~ 1 Mpc) classical double radio sources which we have been making detailed investigations of with Chandra, XMM, the Liverpool Telescope, the WHT, the VLA and MERLIN (Blundell et al 2006, Erlund et al 2007) in order to delineate - at intermediate energies - the nature of the spectral turnover and energy-loss mechanisms in the hotspots and hence quantify the energy transported 0.5-Mpc away from their supermassive black holes.

Publications using this program's data