Seminar: Multi-wavelength Studies of X-ray Bright Extragalactic Jets

Dr Leith Godfrey

ICRAR (Curtin)

Download the pdf poster. 

A decade ago, the launch of Chandra X- ray Observatory, with an order of magnitude improvement in resolution over previous X- ray observatories, marked the beginning of a new era in the study of extragalactic jets. Chandra’s very first observation produced a surprising result: the X-ray emission from quasar jets is too strong to be accounted for by standard emission mechanisms (syn- chrotron, free-free, synchrotron self Comp- ton). The initial solution to this problem invoked beamed inverse Compton scattering of the CMB (IC/CMB), but this model has come into question recently due to a number of significant problems. After 10 years of dedicated Chandra observations and theoretical work, evidence relating to the particle acceleration and X-ray emission mechanisms in kpc-scale quasar jets remain inconclusive.

In this talk I will present some results from my PhD thesis, which comprised a detailed study of the radio, optical and X-ray emission from two bright, and unusual kpc-scale extragalactic jets. The detection of a low energy cut-off in the hotspot of one of these objects, and subsequent modeling, has implications for the jet composition and speed. In another of the objects, conservation of energy and morphological arguments present a severe problem for the IC/CMB model for jet X-ray emission. I will discuss an alternative model that could potentially solve some of the problems of the IC/CMB model.