Research
My research may seem distant and abstract to non-astronomers and I repeatedly get asked by the same people, especially my wife, "What is it you do again?". Here is a brief summary of what I do/did, explained in a reasonably understandable, but still scientific language and with external links where things become complicated.
AGN Feedback
Powerful jets and winds from AGN have a strong impact on the interstellar medium of the host radio galaxy. The deposition of jet mechanical energy and transfer of momentum affects the formation of stars in the host galaxy and the accretion of matter down the gravitational potential onto the central supermassive black hole. AGN jets and winds may, therefore, be responsible for establishing the observed correlation between the mass of the black hole with the mass and the velocity dispersion of the host galaxy's bulge. We test these propositions with high resolution 3D hydrodynamical simulations. This work is done in collaboration with Geoff Bicknell, Masayuki Umemura, Ralph Sutherland, and Joseph Silk. ➜ more
Cosmic-ray modified shocks
Cosmic rays are dynamically and energetically an important constituent of the interstellar medium. Accelerated by shocks supernova remnants, they pervade the interstellar medium and influence the (thermo)dynamics of all phases in a galaxy. I focus on the non-linear modification of shock structures through the back-reaction of accelerated cosmic rays. This work was done in collaboration with Tom Hartquist, Sam Falle, Julian Pittard, John Dyson, Jae-Joon Lee, and John Raymond. ➜ more