Relativistic Jets and Jet-Driven Feedback with AXIS

Despite the fact that jets from black holes were first understood to exist over 40 years ago, we are still in ignorance about many primary aspects of these systems — including the radiation mechanism at high energies, the particle makeup of the jets, and how particles are accelerated, possibly to energies as high as 100 TeV and hundreds of kpc from the central engine. The launch of Chandra in 1999 opened a new era in the studies of resolved jets and high-resolution observations with observatories like Hubble and ALMA have continued to add pieces to the puzzle — sometimes seemly solving a problem, and other times opening a new one. AXIS is an X-ray probe mission concept, designed to be the premiere high-resolution X-ray imaging observatory of the 2030s, rivaling Chandra in angular resolution but with 10 times the sensitivity and a much larger field of view and reach. While the study of X-ray jets essentially began with Chandra, nearly all of the 200+ detections of jet-associated X-rays are in the ‘photon-starved’ regime, which limits our ability to determine the origin of the X-ray emission, particularly at high redshift. Major open questions include the nature of the X-ray emission from the jets themselves, and distinguishing between non-thermal jet emission and that of shocks in jet-driven gas, currently very difficult due to the lack of Chandra sensitivity. This will change dramatically with AXIS, the only X-ray probe which can perform deep observations of resolved, jetted systems and make clear the origin of the X-ray emission and the interplay between jets and their environment, due to the requirements of high angular resolution.