Journal Article

An origin of the radio jet in M87 at the location of the central black hole

Kino, Motoki, Hada, Kazuhiro, Nagai, Hiroshi, Doi, Akihiro, Kawaguchi, Noriyuki, Hagiwara, Yoshiaki

2011

Overview

The relationship between radio jet and black hole Radio jets from active galactic nuclei, such as the nearby galaxy M87, are thought to be powered by the accretion of material into a supermassive black hole. The relative position of this 'central engine' and the bright radio core that marks the base of the jet remain the subject of much speculation. New observations of M87 at six frequencies have been used to determine the position of the radio core to an accuracy of ∼ 20 microarcseconds. The data reveal that the central engine is located close to the radio core, within a distance of 14–23 Schwarzschild radii at 43 GHz. Powerful radio jets from active galactic nuclei are thought to be powered by the accretion of material onto the supermassive black hole (the ‘central engine’) 1 , 2 . M87 is one of the closest examples of this phenomenon, and the structure of its jet has been probed on a scale of about 100 Schwarzschild radii ( R s , the radius of the event horizon) 3 . However, the location of the central black hole relative to the jet base (a bright compact radio ‘core’) remains elusive 4 , 5 . Observations of other jets indicate that the central engines are located about 10 4 –10 6 R s upstream from the radio core 6 , 7 , 8 , 9 . Here we report radio observations of M87 at six frequencies that allow us to achieve a positional accuracy of about 20 microarcseconds. As the jet base becomes more transparent at higher frequencies, the multifrequency position measurements of the radio core enable us to determine the upstream end of the jet. The data reveal that the central engine of M87 is located within 14–23 R s of the radio core at 43 GHz. This implies that the site of material infall onto the black hole and the eventual origin of the jet reside in the bright compact region seen on the image at 43 GHz.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 639/33/34/863 / Accretion / Active and peculiar galaxies (including bl lacertae objects, blazars, seyfert galaxies, markarian galaxies, active galactic nuclei) / Analysis / Astronomy / Astrophysics / Black holes / Black holes (astronomy) / Earth, ocean, space / Engines / Exact sciences and technology / Frequencies of oscillating systems / Humanities and Social Sciences / Jets / letter / multidisciplinary / Origins / Position (location) / Position measurement / Quasars. Active or peculiar galaxies, objects, and systems / Radio / Science / Science (multidisciplinary) / Stars & galaxies / Stellar systems. Galactic and extragalactic objects and systems. The universe / Upstream