Invited Presentation

The Jet Collimation Break: Towards the Paradigm Shift in AGN Jets

Author(s): Masanori Nakamura (ASIAA)

Presenter: Masanori Nakamura (ASIAA)

A magnetized accretion onto the supermassive black hole plays a fundamental role in producing relativistic jets. Theory has been well-established during four decades and it is now time to diagnose with VLBI observations; conical jets have been widely believed in the community since early 1980s, while we examine the M87 jet regarding the formation and propagation of parabolic streams of MHD jets. We also show that parabolic jets may be norm in AGNs by utilizing VLBI observations. Finally, we discuss the jet collimation break (JCB) in AGNs: a transition from parabolic to conical geometry at the sphere of gravitational influence. The JCB reveals the nature of AGN jets under the black hole-galaxy co-evolution. Thus, our discussion overviews the past, present, and future of the AGN jet study.