Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 2019 | Submitted
Journal Article Open

Relativistic Jets from Active Galactic Nuclei

Abstract

The nuclei of most normal galaxies contain supermassive black holes, which can accrete gas through a disk and become active. These active galactic nuclei (AGNs) can form jets that are observed on scales from astronomical units to megaparsecs and from meter wavelengths to TeV energies. High-resolution radio imaging and multiwavelength/messenger campaigns are elucidating the conditions under which this happens. Evidence is presented that: Relativistic AGN jets are formed when the black hole spins and the the accretion disk is strongly magnetized, perhaps on account of gas accreting at high latitude beyond the black hole sphere of influence. AGN jets are collimated close to the black hole by magnetic stress associated with a disk wind. Higher-power jets can emerge from their galactic nuclei in a relativistic, supersonic, and proton-dominated state, and they terminate in strong, hot spot shocks; lower-power jets are degraded to buoyant plumes and bubbles. Jets may accelerate protons to EeV energies, which contribute to the cosmic ray spectrum and may initiate pair cascades that can efficiently radiate synchrotron γ-rays. Jets were far more common when the Universe was a few billion years old and black holes and massive galaxies were growing rapidly. Jets can have a major influence on their environments, stimulating and limiting the growth of galaxies. The observational prospects for securing our understanding of AGN jets are bright.

Additional Information

© 2019 by Annual Reviews. Disclosure Statement: The authors are not aware of any affiliations, memberships, funding, or financial holdings that might be perceived as affecting the objectivity of this review. We thank Ramesh Narayan for his careful and constructive review of the first draft of this article and Noemie Globus for a careful reading of the revised draft. Beyond this, our debt and gratitude to more colleagues than we can possibly list, who have framed our evolving views on AGN jets over the past fifty years, are deep and sincere.

Attached Files

Submitted - 1812.06025.pdf

Files

1812.06025.pdf
Files (7.6 MB)
Name Size Download all
md5:f5ccd38a8a6950429be6bd3388f3e2d5
7.6 MB Preview Download

Additional details

Created:
August 19, 2023
Modified:
October 18, 2023