Revealing structure and the jet connection within AGN coronae

29th Texas Symposium on Relativistic Astrophysics, Cape Town, South Africa (06/12/2017)

Detailed analysis of the reflection and reverberation of X-rays from the innermost regions of AGN accretion discs are revealing, for the first time, the structure and processes within the corona that produces the intense X-ray continuum emission and the extreme variability that is seen.

Observations of AGN by the great X-ray observatories, compared to the predictions of general relativistic ray tracing simulations, have enabled the measurement of the geometry of the corona. They show how it evolves on long and short timescales, giving rise to orders of magnitude variation in luminosity and reveal processes the corona can undergo during transient events, most notably the collimation and ejection of portions of the corona during X-ray flares, reminiscent of the aborted launching of a jet.

The latest X-ray reverberation studies are revealing, for the first time, structure within the corona including a persistent collimated core akin to the base of a jet, even in radio-quiet sources, alongside a second component associated with the accretion disc itself.

This gives us important insight into the processes by which energy is liberated during accretion and a picture is starting to emerge of how these extreme objects are powered and even how jets may be launched.