X-ray reflection and variability from radio jets

Relativistic jets emit radiation spanning the entire electromagnetic spectrum from radio to X-rays and beyond. The goal of this project is to use theoretical models of jets to predict the broad-band spectrum of a jet as a function of distance from the central black hole, paying particular attention to the radio and X-ray wavebands. Jets may produce significant X-ray synchrotron radiation at distances of hundreds to thousands of gravitational radii along the jet, or via inverse Compton processes closer to the base of the jet (for young stars). Some of these X-ray will illuminate the accretion disk producing a backscattered spectrum containing characteristic spectral features such as fluorescence lines that can be measured using X-ray observatories. Furthermore, these jets may be variable (perhaps due to a variable mass injection rate at the base of the jet) with fluctuations propagating outwards along the jet. Modelling these fluctuations will allow time delays between different radio and X-ray energy bands to be calculated which can then be compared with the time delays seen in radio and X-ray observations. The ultimate goal of this project is to provide a suite of models that describe the radio to X-ray spectrum and variability of jet models that can be compared with data.

Jets