Skip to main content

Thank you for visiting 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.

Thermal imaging of dust hiding the black hole in NGC 1068

This article has been updated


In the widely accepted ‘unified model’1 solution of the classification puzzle of active galactic nuclei, the orientation of a dusty accretion torus around the central black hole dominates their appearance. In ‘type-1’ systems, the bright nucleus is visible at the centre of a face-on torus. In ‘type-2’ systems the thick, nearly edge-on torus hides the central engine. Later studies suggested evolutionary effects2 and added dusty clumps and polar winds3 but left the basic picture intact. However, recent high-resolution images4 of the archetypal type-2 galaxy NGC 10685,6, suggested a more radical revision. The images displayed a ring-like emission feature that was proposed to be hot dust surrounding the black hole at the radius where the radiation from the central engine evaporates the dust. That ring is too thin and too far tilted from edge-on to hide the central engine, and ad hoc foreground extinction is needed to explain the type-2 classification. These images quickly generated reinterpretations of the dichotomy between types 1 and 27,8. Here we present new multi-band mid-infrared images of NGC 1068 that detail the dust temperature distribution and reaffirm the original model. Combined with radio data (J.F.G. and C.M.V.I., manuscript in preparation), our maps locate the central engine that is below the previously reported ring and obscured by a thick, nearly edge-on disk, as predicted by the unified model. We also identify emission from polar flows and absorbing dust that is mineralogically distinct from that towards the Milky Way centre.

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

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: IRBis reconstructed images of NGC 1068.
Fig. 2: Apertures for the extraction of infrared SEDs.
Fig. 3: Blackbody SED fits.
Fig. 4: Comparison of infrared and radio images.

Data availability

The raw MATISSE data used in this article are available to qualified researchers at Reduced data are available at

Code availability

The Python code for the emcee sampler is available via The Python code to fit multi-Gaussian models, and spectral energy distributions, is available at The MiRA image reconstruction code is available at The ESO MATISSE pipeline, including IRBis, is available from

Change history

  • 22 March 2022

    In the version of this article initially published, the yellow ellipses in Fig. 1e and the white contours in Fig. 4c drifted from their correct placement in the images. The errors affect presentation only and not underlying results, but are corrected here to improve clarity.


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

    Article  ADS  CAS  Google Scholar 

  2. López-Gonzaga, N. & Jaffe, W. Mid-infrared interferometry of Seyfert galaxies: challenging the standard model. Astron. Astrophys. 591, A128 (2016).

    Article  ADS  Google Scholar 

  3. Asmus, D., Hönig, S. F. & Gandhi, P. The subarcsecond mid-infrared view of local active galactic nuclei. III. Polar dust emission. Astrophys. J. 822, 109–121 (2016).

    Article  ADS  Google Scholar 

  4. GRAVITY Collaboration. An image of the dust sublimation region in the nucleus of NGC 1068. Astron. Astrophys. 634, A1 (2020).

    Article  Google Scholar 

  5. Seyfert, C. K. Nuclear emission in spiral nebulae. Astrophys. J. 97, 28–40 (1943).

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  7. Vermot, P. et al. The hot dust in the heart of NGC 1068’s torus: a 3D radiative model constrained with GRAVITY/VLTi. Astron. Astrophys. 652, A65 (2021).

    Article  Google Scholar 

  8. Prieto, A., Nadolny, J., Fernández-Ontiveros, J. A. & Mezcua, M. Dust in the central parsecs of unobscured AGN: more challenges to the torus. Mon. Not. R. Astron. Soc. 506, 562–580 (2020).

    Article  ADS  Google Scholar 

  9. Hönig, S. F. Redefining the torus: a unifying view of AGNs in the infrared and submillimetre. Astrophys. J. 884, 171 (2019).

    Article  ADS  Google Scholar 

  10. Barvainis, R. Hot dust and the near-infrared bump in the continuum spectra of quasars and active galactic nuclei. Astrophys. J. 320, 537–544 (1987).

    Article  ADS  Google Scholar 

  11. Baskin, A. & Laor, A. Dust inflated accretion disc as the origin of the broad line region in active galactic nuclei. Mon. Not. R. Astron. Soc. 474, 1970–1994 (2018).

    Article  ADS  CAS  Google Scholar 

  12. Jaffe, W. et al. The central dusty torus in the active nucleus of NGC 1068. Nature 429, 47–49 (2004).

    Article  ADS  CAS  PubMed  Google Scholar 

  13. Raban, D., Jaffe, W., Röttgering, H., Meisenheimer, K. & Tristram, K. R. W. W. Resolving the obscuring torus in NGC 1068 with the power of infrared interferometry: revealing the inner funnel of dust. Mon. Not. R. Astron. Soc. 394, 1325–1337 (2009).

    Article  ADS  CAS  Google Scholar 

  14. López-Gonzaga, N., Jaffe, W., Burtscher, L., Tristram, K. R. W. & Meisenheimer, K. Revealing the large nuclear dust structures in NGC 1068 with MIDI/VLTI. Astron. Astrophys. 565, A71 (2014).

    Article  ADS  Google Scholar 

  15. Lopez, B. et al. MATISSE, the VLTI mid-infrared imaging spectro-interferometer. Preprint at (2021).

  16. Hofmann, K.-H., Weigelt, G. & Schertl, D. An image reconstruction method (IRBis) for optical/infrared interferometry. Astron. Astrophys. 565, A48 (2014).

    Article  Google Scholar 

  17. Thiébaut, E. In Proc. SPIE 7013: Optical and Infrared Interferometry (eds Schöller, M. et al.) 70131I (SPIE, 2008).

  18. Högbom, J. A. Aperture synthesis with a non-regular distribution of interferometer baselines. Astron. Astrophys. Suppl. Ser. 15, 417–426 (1974).

    ADS  Google Scholar 

  19. Nenkova, M., Sirocky, M. M., Ivezić, Z. & Elitzur, M. AGN dusty tori. I. Handling of clumpy media. Astrophys. J. 685, 147–159 (2008).

    Article  ADS  Google Scholar 

  20. Fritz, T. K. et al. Line derived infrared extinction toward the Galactic center. Astrophys. J. 737, 73 (2011).

    Article  ADS  Google Scholar 

  21. Min, M., Hovenier, J. W. & de Koter, A. Modelling optical properties of cosmic dust grains using a distribution of hollow spheres. Astron. Astrophys. 432, 909–920 (2005).

    Article  ADS  Google Scholar 

  22. Impellizzeri, C. M. V. et al. Counter-rotation and high-velocity outflow in the parsec-scale molecular torus of NGC 1068. Astrophys. J. Lett. 884, L28–L33 (2019).

    Article  ADS  CAS  Google Scholar 

  23. Greenhill, L. J., Gwinn, C. R., Antonucci, R. & Barvainis, R. VLBI imaging of water maser emission from the nuclear torus of NGC 1068. Astrophys. J. 472, L21–L24 (1996).

    Article  ADS  CAS  Google Scholar 

  24. Gallimore, J. F., Baum, S. A. & O’Dea, C. P. The parsec-scale radio structure of NGC 1068 and the nature of the nuclear radio source. Astrophys. J. 613, 794–810 (2004).

    Article  ADS  CAS  Google Scholar 

  25. Das, V., Crenshaw, D. M., Kraemer, S. B. & Deo, R. P. Kinematics of the narrow-line region in the Seyfert 2 galaxy NGC 1068: dynamical effects of the radio jet. Astron. J. 132, 620–632 (2006).

    Article  ADS  CAS  Google Scholar 

  26. Poncelet, A., Sol, H. & Perrin, G. Dynamics of the ionization bicone of NGC 1068 probed in mid-infrared with VISIR. Astron. Astrophys. 481, 305–317 (2008).

    Article  ADS  CAS  Google Scholar 

  27. García-Burillo, S. et al. ALMA images the many faces of the NGC 1068 torus and its surroundings. Astron. Astrophys. 632, A61 (2019).

    Article  Google Scholar 

  28. Evans, I. N. et al. HST Imaging of the inner 3 arcseconds of NGC 1068 in the light of [O III] lambda 5007. Astrophys. J. 369, L27 (1991).

  29. Gallimore, J. F., Baum, S. A., O’Dea, C. P. & Pedlar, A. The subarcsecond radio structure in NGC 1068. I. Observations and results. Astrophys. J. 458, 136 (1996).

  30. Kishimoto, M. The location of the nucleus of NGC 1068 and the three-dimensional structure of its nuclear region. Astrophys. J. 518, 676–692 (1999).

    Article  ADS  Google Scholar 

  31. Antonucci, R., Hurt, T. & Miller, J. HST ultraviolet spectropolarimetry of NGC 1068. Astrophys. J. 430, 210 (1994).

    Article  ADS  CAS  Google Scholar 

  32. Leinert, C. et al. MIDI – the 10 µm instrument on the VLTI. Astrophys. Space Sci. 286, 73–83 (2003).

    Article  ADS  Google Scholar 

  33. Cruzalèbes, P. et al. A catalogue of stellar diameters and fluxes for mid-infrared interferometry. Mon. Not. R. Astron. Soc. 490, 3158–3176 (2019).

    Article  ADS  Google Scholar 

  34. Burtscher, L., Tristram, K. R. W., Jaffe, W. J. & Meisenheimer, K. In Proc. SPIE 8445: Optical and Infrared Interferometry III (eds Delplancke, F. et al.) 494–506 (SPIE, 2012).

  35. Jaffe, W. J. In Proc. SPIE 5491: New Frontiers in Stellar Interferometry (ed. Traub, W. A.) 715–724 (SPIE, 2004).

  36. Millour, F. et al. In Proc. SPIE 5491: New Frontiers in Stellar Interferometry (ed. Traub, W. A.) 1222–1230 (SPIE, 2004).

  37. Cohen, M. et al. Spectral irradiance calibration in the infrared. X. A self-consistent radiometric all-sky network of absolutely calibrated stellar spectra. Astron. J. 117, 1864–1889 (1999).

    Article  ADS  Google Scholar 

  38. Petrov, R. G. et al. Commissioning MATISSE: operation and performances. Proc. SPIE 11446: Optical and Infrared Interferometry and Imaging VII (eds Tuthill, P. G. et al.) 124–142 (SPIE, 2020).

  39. Bourges, L. et al. JMMC stellar diameters catalogue – JSDC. Version 2. VizieR Online Data Catalog (2017).

  40. Meilland, A. et al. The binary Be star δ Scorpii at high spectral and spatial resolution. I. Disk geometry and kinematics before the 2011 periastron. Astron. Astrophys. 532, A80 (2011).

    Article  Google Scholar 

  41. Leftley, J. H. et al. Resolving the hot dust disk of ESO323-G77. Astrophys. J. 912, 92 (2021).

    Article  Google Scholar 

  42. Lawson, P. R. et al. In Proc. SPIE 5491: Frontiers in Stellar Interferometry (ed. Traub, W. A.) 886–899 (SPIE, 2004).

  43. Cotton, W. et al. In Proc. SPIE 7013: Optical and Infrared Interferometry (eds Schöller, M. et al.) 531–544 (SPIE, 2008).

  44. Baron, F. et al. In Proc. SPIE 8445: Optical and Infrared Interferometry III (eds Delplancke, F. et al.) 470–483 (SPIE, 2012).

  45. Sanchez-Bermudez, J. et al. In Proc. SPIE 9907: Optical and Infrared Interferometry V (eds Melbet, F. et al.) 372–389 (SPIE, 2016).

  46. Hager, W. W. & Park, S. Global convergence of SSM for minimizing a quadratic over a sphere. Math. Comput. 74, 1413–1423 (2005).

    Article  ADS  MathSciNet  MATH  Google Scholar 

  47. Byrd, R. H., Lu, P., Nocedal, J. & Zhu, C. A limited memory algorithm for bound constrained optimization. SIAM J. Sci. Comput. 16, 1190–1208 (1995).

    Article  MathSciNet  MATH  Google Scholar 

  48. Zhu, C., Byrd, R. H., Lu, P. & Nocedal, J. Algorithm 778: L-BFGS-B: Fortran subroutines for large-scale bound-constrained optimization. ACM Trans. Math. Softw. 23, 550–560 (1997).

    Article  MathSciNet  MATH  Google Scholar 

  49. Millour, F. et al. In The 2007 ESO Instrument Calibration Workshop (eds Kaufer, A. & Kerber, F.) 461–470 (Springer, 2008).

  50. Lachaume, R. On marginally resolved objects in optical interferometry. Astron. Astrophys. 400, 795–803 (2003).

    Article  ADS  Google Scholar 

  51. López-Gonzaga, N., Jaffe, W., Burtscher, L., Tristram, K. R. W. & Meisenheimer, K. Revealing the large nuclear dust structures in NGC 1068 with MIDI/VLTI. Astron. Astrophys. 565, A71 (2014).

    Article  ADS  Google Scholar 

  52. Foreman-Mackey, D., Hogg, D. W., Lang, D. & Goodman, J. emcee: the MCMC hammer. Publ. Astron. Soc. Pacif. 125, 306–312 (2013).

    Article  ADS  Google Scholar 

  53. Wells, D. C. In Data Analysis in Astronomy (eds Di Gesù, V. et al.) 195–209 (Springer, 1985).

  54. Greisen, E. W. In Acquisition, Processing and Archiving of Astronomical Images (eds Longo, G. & Sedmak, G.) 125–142 (OAC, FORMEZ, 1990).

  55. Greisen, E. W. In Information Handling in Astronomy – Historical Vistas (ed. Heck, A.) 109–125 (Kluwer, 2003).

  56. Cornwell, T. J. Multiscale CLEAN deconvolution of radio synthesis Images. IEEE J. Sel. Top. Signal Process. 2, 793–801 (2008).

    Article  ADS  Google Scholar 

  57. Cotton, W. D., Jaffe, W., Perrin, G. & Woillez, J. Observations of the inner jet in NGC 1068 at 43 GHz. Astron. Astrophys. 477, 517–520 (2008).

    Article  ADS  CAS  Google Scholar 

  58. Mathis, J. S., Rumpl, W. & Nordsieck, K. H. The size distribution of interstellar grains. Astrophys. J. 217, 425–433 (1977).

    Article  ADS  CAS  Google Scholar 

  59. Zasowski, G., et al. Lifting the dusty veil with near- and mid-infrared photometry. II. A large-scale study of the Galactic infrared extinction law. Astrophys J. 707, 510–523 (2009).

    Article  ADS  Google Scholar 

  60. Köhler, M. & Li, A. On the anomalous silicate absorption feature of the prototypical Seyfert 2 galaxy NGC1068. Mon. Not. R. Astron. Soc. 406, L6–L10 (2010).

    ADS  Google Scholar 

  61. Van Boekel, R., et al. The building blocks of planets within the ‘terrestrial’ region of protoplanetary disks. Nature 432, 479–482 (2004).

    Article  ADS  PubMed  Google Scholar 

  62. Prieto, M. A. et al. The spectral energy distribution of the central parsecs of the nearest AGN. Mon. Not. R. Astron. Soc. 402, 724–744 (2010).

    Article  ADS  Google Scholar 

  63. Isbell, J. W. et al. Subarcsecond mid-infrared view of local active galactic nuclei. IV. The L- and M-band imaging atlas. Astrophys. J. 910, 104 (2021).

    Article  ADS  CAS  Google Scholar 

Download references


We thank ESO and particularly the Cerro Paranal staff for their support in obtaining these observations. The data presented here were taken as part of ESO projects 60.A-9257(commissioning) and 0104.B-0322(A) (MATISSE Guaranteed Time Observations of AGNs). We thank the GRAVITY AGN team for useful scientific discussions and early access to digital versions of their data (programme IDs 0102.B-0667, 0102.C-0205 and 0102.C-0211). MATISSE was defined, funded and built in close collaboration with ESO, by a consortium composed of French (INSU-CNRS in Paris and OCA in Nice), German (MPIA, MPIfR and University of Kiel), Dutch (NOVA and University of Leiden), and Austrian (University of Vienna) institutes. The Conseil Départemental des Alpes-Maritimes in France, the Konkoly Observatory and Cologne University have also provided resources for the manufacture of the instrument. A thought goes to our two deceased OCA colleagues, Olivier Chesneau and Michel Dugué, with us at the origin of the MATISSE project, and with whom we shared many beautiful moments. V.G.R. was partially supported by the Netherlands Organisation for Scientific Research (NWO). J.H.L. acknowledges the support of the French government through the UCA JEDI Investment in the Future project managed by the National Research Agency (ANR) under the reference number ANR-15-IDEX-01.

Author information

Authors and Affiliations



V.G.R., J.W.I., W.J., R.G.P., K.-H.H., F.M., J.H.L., A. Meilland: observing, data reduction, calibration, modelling, interpretation. B.L., S.L., F.A., S.R.-D., P.C., P. Berio, F.B., T.H., G.W., P.A., U.B., U.G., M. Heininger, M.L., A. Matter, D.S., P.S., J.W., G.Z., P. Bendjoya: MATISSE instrument design, fabrication, and commissioning, calibration. L.B., G.W., R.v.B., P.S., J.-C.A., M. Hogerheijde, J.-U.P.: scientific planning. J.F.G., C.M.V.I., K.T., L.B., C.P.: observing. W.C.D., C.D., J.D., V.H., J.H., L.K., E.K., L.L., E.P., A.S., J.V., S.W., L.B.F.M.W., G.Y.: interpretation.

Corresponding author

Correspondence to Violeta Gámez Rosas.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature thanks Robert Antonucci and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data figures and tables

Extended Data Fig. 1 MATISSE faint calibrator data and uv coverage.

a,Instrumental squared visibility (ISV) and b, non-calibrated closure phases (T3PHI) of calibrators observed during the months of September 2018, May 2019 and June 2019, at 3.4 μm. Data points are colour-coded by their diameters, and the size of the circles correspond to the average coherence times of the observations. The vertical blue strip covers the approximate correlated flux of NGC 1068 at the same wavelength. Error bars show one standard deviation of data. c, uv coverage of MATISSE observations.

Extended Data Fig. 2 Comparison of photometry of the models and image reconstructions.

The photometry between methods generally agrees in spectral shape between different methods. The most notable exceptions are SE and E3 which still produce similar temperatures from SED modelling between methods.

Extended Data Fig. 3 SED black body model fits to MATISSE aperture photometry.

The figures are labelled with the aperture names defined in Fig. 2. The shaded areas show all models falling inside 1 sigma of the photometry, considering both pure amorphous olivine (magenta) and a mix of olivine and 20% amorphous carbon by weight (cyan). The plots for apertures E1 and SE are in the main article.

Extended Data Fig. 4 NGC 1068 N-band data compared to best multi-Gaussian model.

a, Squared visibilities for NGC 1068. The blue lines show observed values, averaged over sub-exposures; the thin grey lines show individual sub-exposures in order to illustrate the measurement uncertainties, but are often hidden behind the blue lines. The green points with error bars show values predicted by the multi-Gaussian models from Methods. The error bars represent the r.m.s. sum of the measurement errors and the uncertainties of the model parameters. The distance between models and observations shows that a limited number of Gaussians cannot exactly represent the true sky or that we do not have a sufficient uv coverage and/or resolution. The grey bands mark the atmospheric non-transmission band. The labels indicate the telescope pairs for each baseline, the baseline length (m) and position angle (degrees), and the specific exposure label from the observation log described in the main paper. b, Closure phases (degrees) using the same colour code as above. The labels indicate the telescope triplets and the specific exposure label from the observing log.

Extended Data Fig. 5 NGC 1068 spectra.

a, Average single telescope spectrum of NGC 1068 in LM-bands (black solid line) and N-band (blue solid line). The error bars represent uncertainties estimated from the differences between different dates and calibrators. The yellow stars refer to VLT/ISAAC L’ -and M-band single-dish flux estimates from ref. 63, while the green triangle corresponds to a VLT/NACO M-band flux from ref. 62. b, The silicate absorption feature observed on two baselines at high spectral resolution (R ~ 300) during a single MATISSE commissioning snapshot. The 85 m baseline shows the broader, double-peaked profile characteristic of crystalline, reprocessed grains61. The difference between the curves shows that the crystallinity varies over the source.

Extended Data Fig. 6 MATISSE N-band squared visibilities and closure phases.

The quantities plotted, and the symbols used are the same as Extended Data Fig. 4 for the N band.

Extended Data Fig. 7 Comparison of reconstructed images at four wavelengths from four algorithms.

From left to right: the MIRA image reconstruction, the IRBis image reconstruction, the overfitted point source model (convolved with the beam), and Gaussian model for four selected wavelengths. The plot uses a 0.6 power colour scaling for visual purposes. Each method reveals similar structures and morphology.

Extended Data Fig. 8 Evaluation of artefacts created by IRBis image reconstruction.

In order to quantify the fidelity of the reconstructions shown in Fig. 1, we performed analogous reconstruction on an artificial model. The model consisted of seven Gaussians, similar to our multi-Gaussian model for the dust emission (Methods). We simulated visibility and closure phase data for this model for our uv coverage; we added noise to the simulated data similar to that in the observations. We then performed image reconstruction using IRBis with identical reconstruction parameters to those used in Fig. 1. a, The input 7-Gaussian model. b, The IRBis reconstructed image. c, The reconstructed image minus the input model. In all cases the colour scale represents the fraction of the peak intensity of the original model. The r.m.s. errors in the residual maps were 2.3% of the peak brightness. This indicated that most of the artefacts present in Fig. 1 result from the uv coverage rather than noise on the observed quantities. In Fig. 1 we have drawn white contours at 3σ = 6% of the peak. Features brighter than this certainly represent true source emission.

Extended Data Fig. 9 NGC 1068 image reconstruction data.

a, Image representation of models obtained from the Gaussian modelling approach described in Methods. We use square root intensity scale. b, Image reconstruction with MIRA using different methods (see Methods). From left to right: using total variation (TV) regularizer, on a large bandwidth ('grey' reconstruction); using the same regularizer, but independently reconstructing images at each wavelength, and computing a median over the wavelength interval; using maximum entropy regularizer (grey reconstruction); using smoothness regularizer (grey reconstruction).

Extended Data Table 1 Parameters for IRBis image reconstruction, Gaussian modelling and SED fitting

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Gámez Rosas, V., Isbell, J.W., Jaffe, W. et al. Thermal imaging of dust hiding the black hole in NGC 1068. Nature 602, 403–407 (2022).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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.


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