Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

The central dusty torus in the active nucleus of NGC 1068

Abstract

Active galactic nuclei (AGNs) display many energetic phenomena—broad emission lines, X-rays, relativistic jets, radio lobes—originating from matter falling onto a supermassive black hole. It is widely accepted that orientation effects play a major role in explaining the observational appearance of AGNs. Seen from certain directions, circum-nuclear dust clouds would block our view of the central powerhouse1,2. Indirect evidence suggests that the dust clouds form a parsec-sized torus-shaped distribution. This explanation, however, remains unproved, as even the largest telescopes have not been able to resolve the dust structures. Here we report interferometric mid-infrared observations that spatially resolve these structures in the galaxy NGC 1068. The observations reveal warm (320 K) dust in a structure 2.1 parsec thick and 3.4 parsec in diameter, surrounding a smaller hot structure. As such a configuration of dust clouds would collapse in a time much shorter than the active phase of the AGN3, this observation requires a continual input of kinetic energy to the cloud system from a source coexistent with the AGN.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Images and model of emission from NGC 1068 at increasing magnification.
Figure 2: Observed MIDI spectra from the nucleus of NGC 1068 compared with two-component gaussian model predictions.

Similar content being viewed by others

References

  1. Antonucci, R. Unified models for active nuclei and quasars. Annu. Rev. Astron. Astrophys. 31, 473–521 (1993)

    Article  ADS  CAS  Google Scholar 

  2. Urry, C. M. & Padovani, P. Unified schemes for radio-loud active galactic nuclei. Publ. Astron. Soc. Pacif. 107, 803–845 (1995)

    Article  ADS  Google Scholar 

  3. Krolik, J. H. & Begelman, M. C. Molecular tori in Seyfert galaxies: Feeding the monster and hiding it. Astrophys. J. 329, 702–711 (1998)

    Article  ADS  Google Scholar 

  4. Antonucci, R. J. & Miller, J. S. Spectropolarimetry and the nature of NGC 1068. Astrophys. J. 297, 621–632 (1985)

    Article  ADS  CAS  Google Scholar 

  5. Lumsden, S. L. et al. Near- and mid-infrared imaging polarimetry of NGC 1068. Mon. Not. R. Astron. Soc. 303, 209–220 (1999)

    Article  ADS  Google Scholar 

  6. Leinert, C. et al. Ten-micron instrument MIDI: getting ready for observations on the VLTI. Proc. SPIE 4838, 893–904 (2003)

    Article  ADS  Google Scholar 

  7. Glindermann, A. et al. The VLTI—A Status Report. Proc. SPIE 4838, 89–100 (2003)

    Article  ADS  Google Scholar 

  8. Muxlow, T. W. B., Pedlar, A., Holloway, A. J., Gallimore, J. F. & Antonucci, R. R. J. The compact radio nucleus of the Seyfert galaxy NGC 1068. Mon. Not. R. Astron. Soc. 278, 854–860 (1996)

    Article  ADS  Google Scholar 

  9. Bock, J. J. et al. High spatial resolution imaging of NGC 1068 in the mid-infrared. Astron. J. 190, 2904–2919 (2000)

    Article  ADS  Google Scholar 

  10. Lutz, D. et al. ISO-SWS spectroscopy of NGC 1068. Astrophys. J. 536, 697–709 (2000)

    Article  ADS  CAS  Google Scholar 

  11. Kemper, F., Vriend, W. J. & Tielens, A. G. G. M. ISO spectra of Sgr A. Astrophys. J. (submitted)

  12. Speck, A. K., Barlow, J. J., Sylvester, F. J. & Hofmeister, A. M. Dust features in the 10 micron infrared spectra of oxygen-rich evolved stars. Astron. Astrophys. Suppl. 146, 437–464 (2000)

    Article  ADS  CAS  Google Scholar 

  13. Maiolino, R. et al. Dust in active nuclei. I. Evidence for anomalous properties. Astron. Astrophys. 365, 28–36 (2001)

    Article  ADS  CAS  Google Scholar 

  14. Pier, E. A. & Krolik, J. H. Infrared spectra of obscuring dust tori around active galactic nuclei. Astrophys. J. 401, 99–109 (1992)

    Article  ADS  CAS  Google Scholar 

  15. Efstathiou, A., Hough, J. H. & Young, S. A model for the infrared continuum spectrum of NGC 1068. Mon. Not. R. Astron. Soc. 277, 1134–1144 (1995)

    Article  ADS  CAS  Google Scholar 

  16. Granato, G. L., Danese, L. & Franceschini, A. Thick tori around active galactic nuclei: the case for extended tori and consequences for their X-ray and infrared emission. Astrophys. J. 486, 147–159 (1997)

    Article  ADS  CAS  Google Scholar 

  17. Schartmann, M. Dust Tori in Active Galactic Nuclei. Thesis, Univ. Heidelberg (2003)

    Google Scholar 

  18. Crenshaw, D. M. & Kraemer, S. B. Resolved spectroscopy of the narrow-line region in NGC 1068: Kinematics of the ionized gas. Astrophys. J. 532, L101–L104 (2000)

    Article  ADS  CAS  Google Scholar 

  19. Nenkova, M., Ivezić, Z. & Elitzur, M. Dust emission from active galactic nuclei. Astrophys. J. 570, L9–L12 (2002)

    Article  ADS  CAS  Google Scholar 

  20. Bruhweiler, F. C., Miskey, C. L., Smith, A. M., Landsman, W. & Malumuth, E. Ionization, extinction and spiral structure in the inner disk of NGC 1068. Astrophys. J. 546, 866–876 (2001)

    Article  ADS  CAS  Google Scholar 

  21. Bland-Hawthorn, J. et al. The Ringberg standards for NGC 1068. Astrophys. Space Sci. 248, 9–19 (1997)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

This Letter is based on observations carried out at the European Southern Observatory, Paranal, Chile, in the framework of the VLTI science demonstration program. MIDI could not have been built without contributions from many people, including E. J. Bakker, P. Ballester, S. Beckwith, P. Biereichel, A. Böhm, W. D. Cotton, S. Damstra, A. Glindemann, B. Grimm, J. de Jong, N. Haddad, H. Hanenburg, T. Henning, N. Housen, S. Hippler, W. Laun, S. Ligori, R. Lenzen, B. Lopez, O. von der Lühe, R. J. Mathar, J. Meisner, S. Morel, W. Morr, U. Neumann, R.-R. Rohloff, P. Schuller, N. Salm, C. Storz, A. Wallander and K. Wagner. We thank ESO staff at Garching, Santiago de Chile, and Cerro Paranal (Chile), for operating MIDI.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to W. Jaffe.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Jaffe, W., Meisenheimer, K., Röttgering, H. et al. The central dusty torus in the active nucleus of NGC 1068. Nature 429, 47–49 (2004). https://doi.org/10.1038/nature02531

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature02531

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing