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A direct image of the obscuring disk surrounding an active galactic nucleus

Nature volume 388, pages 852–854 (1997)Cite this article

Abstract

Active galactic nuclei (AGN) are generally accepted to be powered by the release of gravitational energy in a compact accretion disk surrounding a massive black hole1,2; such disks are also thought necessary to collimate the powerful radio jets seen in some AGN3. The unifying classification schemes for AGN further propose that differences in their appearance can be attributed to the opacity of the accreting material, which may obstruct our view of the central region of some systems. The popular model for the obscuring medium is a parsec-scale disk of dense molecular gas4, although evidence for such disks has been mostly indirect, as their angular size is much smaller than the resolution of conventional telescopes. Here we report direct images of a parsec-scale disk of ionized gas within the nucleus of NGC1068, the archetype of obscured AGN. The disk is viewed nearly edge-on, and individual clouds observed within the ionized disk are opaque to high-energy radiation, consistent with the unifying classification schemes. The projected axes of the disk and AGN are aligned, from which we infer that the ionized gas disk traces the outer regions of the long-sought inner accretion disk.

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Figure 1: VLBI images of the radio component S1 of NGC1068.
Figure 2: Diagrams of our model of the AGN of NGC1068 and its environs.

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Acknowledgements

The VLBA and VLA are operated by the National Radio Astronomy Observatory which is operated by Associated Universities, Inc., under cooperative agreement with the NSF. J.F.G. received support from a Collaborative Visitor's Grant from the Space Telescope Science Institute.

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Authors and Affiliations

  1. Max-Planck-Institut für extraterrestrische Physik, Postfach 1603, D-85740, Garching bei München, Germany

    Jack F. Gallimore

  2. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, 21218, Maryland, USA

    Stefi A. Baum & Christopher P. O'Dea

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  1. Jack F. Gallimore
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  3. Christopher P. O'Dea
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Correspondence to Jack F. Gallimore.

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Gallimore, J., Baum, S. & O'Dea, C. A direct image of the obscuring disk surrounding an active galactic nucleus. Nature 388, 852–854 (1997). https://doi.org/10.1038/42201

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