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Thermal imaging of dust hiding the black hole in NGC 1068

Naturevolume 602, pages403–407 (2022)Cite this article

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Abstract

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.

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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.

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Data availability

The raw MATISSE data used in this article are available to qualified researchers athttp://archive.eso.org/eso/eso_archive_main.html. Reduced data are available athttps://github.com/VioletaGamez/NGC1068_MATISSE.

Code availability

The Python code for the emcee sampler is available viahttps://emcee.readthedocs.io. The Python code to fit multi-Gaussian models, and spectral energy distributions, is available at https://doi.org/10.5281/zenodo.5599363. The MiRA image reconstruction code is available athttps://github.com/emmt/MiRA. The ESO MATISSE pipeline, including IRBis, is available fromhttps://www.eso.org/sci/software/pipelines/matisse/matisse-pipe-recipes.html.

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.

References

  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.Nature429, 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 athttps://arxiv.org/abs/2110.15556 (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. InProc. 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. InProc. SPIE 8445: Optical and Infrared Interferometry III (eds Delplancke, F. et al.) 494–506 (SPIE, 2012).

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

  36. Millour, F. et al. InProc. 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 Cataloghttps://cdsarc.cds.unistra.fr/viz-bin/cat/II/346 (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. InProc. SPIE 5491: Frontiers in Stellar Interferometry (ed. Traub, W. A.) 886–899 (SPIE, 2004).

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

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

  45. Sanchez-Bermudez, J. et al. InProc. 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. InThe 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. InData Analysis in Astronomy (eds Di Gesù, V. et al.) 195–209 (Springer, 1985).

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

  55. Greisen, E. W. InInformation 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.Nature432, 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 

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Acknowledgements

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

  1. Leiden Observatory, Leiden University, Leiden, Netherlands

    Violeta Gámez Rosas, Walter Jaffe, Leonard Burtscher, Michiel Hogerheijde, Caterina M. V. Impellizzeri & Jozsef Varga

  2. Max Planck Institute for Astronomy, Heidelberg, Germany

    Jacob W. Isbell, Klaus Meisenheimer, Thomas Henning, Roy van Boekel, Uwe Graser, Lucia Klarmann, Michael Lehmitz, Jörg-Uwe Pott & Gideon Yoffe

  3. Laboratoire Lagrange, Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Nice, France

    Romain G. Petrov, James H. Leftley, Florentin Millour, Anthony Meilland, Bruno Lopez, Stéphane Lagarde, Philippe Berio, Fatme Allouche, Sylvie Robbe-Dubois, Pierre Cruzalèbes, Pierre Antonelli, Philippe Bendjoya, Julien Drevon, Vincent Hocdé, Elena Kokoulina, Alexis Matter & Philippe Stee

  4. Max Planck Institute for Radio Astronomy, Bonn, Germany

    Karl-Heinz Hofmann, Gerd Weigelt, Udo Beckmann, Matthias Heininger & Dieter Schertl

  5. Department of Astrophysics, IMAPP, Radboud University, Nijmegen, Netherlands

    Laurens B. F. M. Waters

  6. SRON Netherlands Institute for Space Research, Leiden, Netherlands

    Laurens B. F. M. Waters

  7. ASTRON, Dwingeloo, Netherlands

    Felix Bettonvil

  8. Université Grenoble Alpes, CNRS, IPAG, Grenoble, France

    Jean-Charles Augereau

  9. Goddard Space Flight Center, NASA, Greenbelt, MD, USA

    William C. Danchi

  10. Anton Pannekoek Institute, University of Amsterdam, Amsterdam, Netherlands

    Carsten Dominik & Michiel Hogerheijde

  11. Department of Physics and Astronomy, Bucknell University, Lewisburg, PA, USA

    Jack F. Gallimore

  12. Department of Astrophysics University of Vienna, Vienna, Austria

    Josef Hron

  13. Physikalisches Institut der Universität zu Köln, Cologne, Germany

    Lucas Labadie

  14. European Southern Observatory, Santiago, Chile

    Claudia Paladini, Konrad Tristram & Gerard Zins

  15. Centre d’Etudes de Saclay, Gif-sur-Yvette, France

    Eric Pantin

  16. Sydney Institute for Astronomy, University of Sydney, Sydney, Australia

    Anthony Soulain

  17. European Southern Observatory, Garching, Germany

    Julien Woillez

  18. Institute of Theoretical Physics and Astrophysics, University of Kiel, Kiel, Germany

    Sebastian Wolf

Authors
  1. Violeta Gámez Rosas
  2. Jacob W. Isbell
  3. Walter Jaffe
  4. Romain G. Petrov
  5. James H. Leftley
  6. Karl-Heinz Hofmann
  7. Florentin Millour
  8. Leonard Burtscher
  9. Klaus Meisenheimer
  10. Anthony Meilland
  11. Laurens B. F. M. Waters
  12. Bruno Lopez
  13. Stéphane Lagarde
  14. Gerd Weigelt
  15. Philippe Berio
  16. Fatme Allouche
  17. Sylvie Robbe-Dubois
  18. Pierre Cruzalèbes
  19. Felix Bettonvil
  20. Thomas Henning
  21. Jean-Charles Augereau
  22. Pierre Antonelli
  23. Udo Beckmann
  24. Roy van Boekel
  25. Philippe Bendjoya
  26. William C. Danchi
  27. Carsten Dominik
  28. Julien Drevon
  29. Jack F. Gallimore
  30. Uwe Graser
  31. Matthias Heininger
  32. Vincent Hocdé
  33. Michiel Hogerheijde
  34. Josef Hron
  35. Caterina M. V. Impellizzeri
  36. Lucia Klarmann
  37. Elena Kokoulina
  38. Lucas Labadie
  39. Michael Lehmitz
  40. Alexis Matter
  41. Claudia Paladini
  42. Eric Pantin
  43. Jörg-Uwe Pott
  44. Dieter Schertl
  45. Anthony Soulain
  46. Philippe Stee
  47. Konrad Tristram
  48. Jozsef Varga
  49. Julien Woillez
  50. Sebastian Wolf
  51. Gideon Yoffe
  52. Gerard Zins

Contributions

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 toVioleta Gámez Rosas.

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The authors declare no competing interests.

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

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Extended data figures and tables

Extended Data Fig. 1 MATISSE faint calibrator data anduv coverage.

a,Instrumental squared visibility (ISV) andb, 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 sufficientuv 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 ouruv 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 theuv 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

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Gámez Rosas, V., Isbell, J.W., Jaffe, W.et al. Thermal imaging of dust hiding the black hole in NGC 1068.Nature602, 403–407 (2022). https://doi.org/10.1038/s41586-021-04311-7

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