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H2O MegaMaser emission in NGC 4258 indicative of a periodic disc instability

Nature Astronomy volume 6, pages 976–983 (2022)Cite this article

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Abstract

H2O MegaMaser emission may arise from thin gas discs surrounding the massive nuclei of galaxies such as NGC 4258, but the physical conditions responsible for the amplified emission are unclear. A detailed view of these regions is possible using the very high angular resolution afforded by space very long baseline interferometry (SVLBI). Here we report SVLBI experiments conducted using the orbiting RadioAstron Observatory that have resulted in detections of the H2O 22 GHz emission in NGC 4258, with Earth–space baselines of 1.3, 9.5 and 19.5 Earth diameters. Observations at the highest angular resolutions of 11 and 23 μas show distinct and regularly spaced regions within the rotating disc, at an orbital radius of about 0.126 pc. These observations at three subsequent epochs also indicate a time evolution of the emission features, with a sudden rise in amplitude followed by a slow decay. The formation of these emission regions, their regular spacing and their time-dependent behaviour appear consistent with the occurrence of a periodic magneto-rotational instability in the disc. This type of shear-driven instability within the differentially rotating disc has been suggested to be the mechanism governing the radial momentum transfer and viscosity within a mass-accreting disc. The connection of the H2O MegaMaser activity with the magneto-rotational instability activity would make it an indicator of the mass-accretion rate in the nuclear disc of the host galaxy.

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Fig. 1: The first experiment RAKS07AT for NGC 4258 with a 9.1–9.8 ED Earth–space baseline taken on 5 February 2014.
Fig. 2: Experiment RAGS11AF for NGC 4258 with a 0.5–1.9 ED Earth–space baselines taken on 18 December 2014.
Fig. 3: Experiment RAGS18H for NGC 4258 with a 19.5 ED Earth–space baseline taken on 17 March 2016.
Fig. 4: Component velocities and velocity drifts between three epochs.
Fig. 5: Schematic cartoon of the non-linear development of a MRI and how velocity-coherent radial column densities may develop.

Data availability

The correlated data for RadioAstron experiments RAGS11AF, RAKS07AT and RAGS18H are available from the RadioAstron Data Archive at the Astrospace Centre of the PN Lebedev Physics Institute ASC LPI) in Moscow at http://opendata.asc.rssi.ru/index.php.

Code availability

Data reduction has been performed with AIPS, which has been developed by the National Radio Astronomy Observatory and is documented and available at http://www.aips.nrao.edu/index.shtml. Plotting procedures have been used from the MATLAB Toolbox distributed by MathWorks, Inc. at https://www.mathworks.com/products/matlab.html. The PIMA software package for processing individual baselines can be found at http://astrogeo.org/pima/. A description of the ASC Software correlator can be found in the literature17.

References

  1. Kardashev, N. S. et al. RadioAstron—a telescope with a size of 300 000 km: main parameters and first observational results. Astron. Rep. 57, 153–194 (2013).

    Article  ADS  Google Scholar 

  2. Lo, K. Y. MegaMasers and galaxies. Annu. Rev. Astron. Astrophys. 43, 625 (2005).

    Article  ADS  Google Scholar 

  3. Zhu, G. et al. Optical properties of host galaxies of extragalactic nuclear water masers. Astrophys. J. 742, 73–84 (2011).

    Article  ADS  Google Scholar 

  4. Braatz, J. A Catalog of Galaxies Detected in H2O Maser Emission (NRAO, 2014); https://safe.nrao.edu/wiki/bin/view/Main/PrivateWaterMaserList

  5. Kuo, C. Y. et al. The MegaMaser Cosmology Project. XII. VLBI imaging of H2O maser emission in three active galaxies and the effect of AGN winds on disc dynamics. Astrophys. J. 892, 18–39 (2020).

    Article  ADS  Google Scholar 

  6. Haschick, A. D., Baan, W. A. & Peng, E. The masering torus in NGC 4258. Astrophys. J. 437, L35–L38 (1994).

    Article  ADS  Google Scholar 

  7. Miyoshi, M. et al. Evidence for a black hole from high rotation velocities in a sub-parsec region of NGC 4258. Nature 373, 127–129 (1995).

    Article  ADS  Google Scholar 

  8. Greenhill, L. J. et al. Detection of a subparsec diameter disc in the nucleus of NGC 4258. Astrophys. J. 440, 619–627 (1995).

    Article  ADS  Google Scholar 

  9. Herrnstein, J. R. et al. A geometric distance to the galaxy NGC 4258 from orbital motions in a nuclear gas disc. Nature 400, 539–541 (1999).

    Article  ADS  Google Scholar 

  10. Herrnstein, J. R. et al. The geometry of and mass accretion rate through the maser accretion disc in NGC 4258. Astrophys. J. 629, 719–738 (2005).

    Article  ADS  Google Scholar 

  11. Argon, A. L. et al. Toward a new geometric distance to the active galaxy NGC 4258. I. VLBI monitoring of water maser emission. Astrophys. J. 659, 1040–1062 (2007).

    Article  ADS  Google Scholar 

  12. Humphreys, E. M. L. et al. Towards a new geometric distance to the active galaxy NGC 4258. II Centripetal accelerations and investigation of spiral structure. Astrophys. J. 672, 800–816 (2008).

    Article  ADS  Google Scholar 

  13. Humphreys, E. M. L. et al. Towards a new geometric distance to the active galaxy NGC 4258: III Final results and the Hubble constant. Astrophys. J. 775, 13–22 (2013).

    Article  ADS  Google Scholar 

  14. Herrnstein, J. R. et al. VLBA continuum observations of NGC 4258: constraints on the advection-dominated accretion flow. Astrophys. J. 497, L69–L73 (1998).

    Article  ADS  Google Scholar 

  15. Doi, A. et al. Nuclear radio jet from a low-luminosity active galactic nucleus in NGC 4258. Astrophys. J. 765, 63–73 (2013).

    Article  ADS  Google Scholar 

  16. Baan, W. A. Powerful extragalactic masers. Nature 315, 26–31 (1985).

    Article  ADS  Google Scholar 

  17. Likhachev, S. F. et al. Software correlator for the RadioAstron mission. J. Astron. Instr. 6, 1750004 (2017).

    Article  Google Scholar 

  18. Frank, J., King, A. & Raine, D. J. Accretion Power in Astrophysics 104–129 (Cambridge Univ. Press, 2002).

  19. Fruscione, A. et al. X-ray luminosity and absorption column fluctuations in the H2O maser galaxy NGC 4258 from weeks to years. Astrophys. J. 624, 103–117 (2005).

    Article  ADS  Google Scholar 

  20. Neufeld, D. A., Maloney, P. R. & Conger, S. Water maser emission from X-ray-heated circumnuclear gas in active galaxies. Astrophys. J. 436, L127–L130 (1994).

    Article  ADS  Google Scholar 

  21. Neufeld, D. A. & Maloney, P. R. The mass accretion rate through the masing molecular disc in the active galaxy NGC 4258. Astrophys. J. 447, L17–L20 (1995).

    Article  ADS  Google Scholar 

  22. Maoz, E. & McKee, C. Doppler shift asymmetry in high-velocity maser emission from shocks in circumnuclear discs. Astrophys. J. 494, 218–235 (1998).

    Article  ADS  Google Scholar 

  23. Wallin, B. K., Watson, W. D. & Wyld, H. W. Spectra of maser radiation from a turbulent, circumnuclear accretion disc. Astrophys. J. 495, 774–785 (1998).

    Article  ADS  Google Scholar 

  24. Wallin, B. K., Watson, W. D. & Wyld, H. W. Spectra of maser radiation from a turbulent, circumnuclear accretion disc. II. High-velocity features. Astrophys. J. 517, 682–691 (1999).

    Article  ADS  Google Scholar 

  25. Kartje, J., Königl, A. & Elitzur, M. Megamaser discs in active galactic nuclei. Astrophys. J. 513, 180–196 (1999).

    Article  ADS  Google Scholar 

  26. Babovskaya, N. S. & Varshalovich, D. A. A model of the molecular accretion disc and H2O maser in the nucleus of the galaxy NGC 4258. Astron. Lett. 26, 144–152 (2000).

    Article  ADS  Google Scholar 

  27. Griv, E. Sausage and kink oscillations in astrophysical disc configurations. Phys. Rev. Lett. 106, 1103 (2011).

    Article  ADS  Google Scholar 

  28. Kratter, K. & Lodato, G. Gravitational instabilities in circumstellar discs. Annu. Rev. Astron. Astrophys. 54, 271–311 (2016).

    Article  ADS  Google Scholar 

  29. Renaud, F. et al. A sub-parsec resolution simulation of the Milky Way: global structure of the interstellar medium and properties of molecular clouds. Mon. Not. R. Astron. Soc. 436, 1836–1851 (2013).

    Article  ADS  Google Scholar 

  30. Toomre, A. On the gravitational stability of a disc of stars. Astrophys. J. 139, 1217–1238 (1964).

    Article  ADS  Google Scholar 

  31. Toomre, A. in The Structure and Evolution of Normal Galaxies (eds Fall, S. M. & Lynden-Bell, D.) 111–136 (Cambridge Univ. Press, 1981).

  32. Modjaz, M., Moran, J. M., Kondratko, P. T. & Greenhill, L. J. Probing the magnetic field at subparsec radii in the accretion disc of NGC 4258. Astrophys. J. 626, 104–119 (2005).

    Article  ADS  Google Scholar 

  33. Shakura, N. I. & Sunyaev, R. A. Black holes in binary systems. Observational appearance. Astron. Astrophys. 24, 337–355 (1973).

    ADS  Google Scholar 

  34. Balbus, A. A. & Hawley., J. F. A powerful local shear instability in weakly magnetized discs. I Linear analysis. Astrophys. J. 376, 214–222 (1991).

    Article  ADS  Google Scholar 

  35. Hawley, J. F. & Balbus, S. A. A powerful local shear instability in weakly magnetized discs II Nonlinear evolution. Astrophys. J. 376, 223–233 (1991).

    Article  ADS  Google Scholar 

  36. Balbus, S. A., Hawley, J. F. & Stone, J. M. Nonlinear stability, hydrodynamical turbulence, and transport in discs. Astrophys. J. 467, 76–86 (1996).

    Article  ADS  Google Scholar 

  37. Hogg, J. D. & Reynolds, C. S. The dynamics of truncated black hole accretion discs. I. Viscous hydrodynamic case. Astrophys. J. 843, 80–94 (2017).

    Article  ADS  Google Scholar 

  38. Hawley, J. F., Gammie, C. F. & Balbus, S. A. Local three-dimensional magnetohydrodynamic simulations of accretion discs. Astrophys. J. 440, 742–763 (1995).

    Article  ADS  Google Scholar 

  39. Petrov, L., Kovalev, Y. Y., Fomalont, E. B. & Gordon, D. The Very Long Baseline Array Galactic Plane Survey—VGaPS. Astron. J. 142, 35–57 (2011).

    Article  ADS  Google Scholar 

  40. Kuo, C. Y. et al. On estimating the mass of Keplerian accretion discs in H2O maser galaxies. Astrophys. J. 859, 172–183 (2018).

    Article  ADS  Google Scholar 

  41. Elitzur, M. Astronomical Masers 47–112 (Kluwer Academic Publishers, 1992).

Download references

Acknowledgements

We dedicate this paper to the memory of our colleague and friend Nikolai Kardashev, a man of great vision, who persevered to realize the RadioAstron mission. We thank the observatory staff of the ground telescope stations Effelsberg, Green Bank, Torun, Yebes and the Kwazar stations Kalyazin, Svetloe and Badary for their participation in the observations. These observations have been correlated at the ASC DiFX correlator and we thank the Correlator Team members for their contributions, their repeated re-correlation efforts and their unfailing support of this project. We also thank the other members of the H2O MegaMaser Team for their support for this project: A. Alakoz, S. Ellingsen, I. Litovchenko, J. Moran and A. Tolmachev. We thank E. Vorobyov (University of Vienna) for valuable discussions about the stability criteria for the disc. The RadioAstron project has been led by the AstroSpace Centre of the Lebedev Physical Institute of the Russian Academy of Sciences and the Lavochkin Scientific and Production Association under a contract with the State Space Corporation ROSCOSMOS, in collaboration with partner organizations in Russia and other countries. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under a cooperative agreement by Associated Universities, Inc. The European VLBI Network is a joint facility of independent European, African, Asian and North American radio astronomy institutes. W.A.B. acknowledges the support from the National Natural Science Foundation of China under grant no. 11433008 and the Chinese Academy of Sciences President’s International Fellowship Initiative under grant nos. 2019VMA0040, 2021VMA0008 and 2022VMA0019. T.A. acknowledges the grant support from the Youth Innovation Promotion Association of CAS. AMS was supported by the Ministry of Education and Science of Russia (the basic part of the State assignment, K 1567 no. FEUZ-2020-0030).

Author information

Authors and Affiliations

  1. Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi, China

    Willem A. Baan & Christian Henkel

  2. Netherlands Institute for Radio Astronomy ASTRON, Dwingeloo, Netherlands

    Willem A. Baan

  3. Shanghai Astronomical Observatory, Chinese Academy of Science, Shanghai, China

    Willem A. Baan & Tao An

  4. Max-Planck-Institut für Radioastronomie, Bonn, Germany

    Christian Henkel

  5. Astronomy Deptartment, King Abdulaziz University, Jeddah, Saudi Arabia

    Christian Henkel

  6. Amanogawa Galaxy Astronomy Research Center, Graduate School of Science and Engineering, Kagoshima University, Kagoshima, Japan

    Hiroshi Imai

  7. AstroSpace Centre, Lebedev Institute, Moscow, Russia

    Vladimir Kostenko

  8. Astronomical Observatory, Ural Federal University, Ekaterinburg, Russia

    Andrej Sobolev

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Contributions

W.A.B. coordinated the research, carried out the data reduction and wrote the manuscript. W.A.B., T.A., C.H., H.I., V.K. and A.S. contributed to the discussion and interpretation of the data and provided comments on the manuscript. W.A.B. served as Principal Investigator of the RadioAstron MegaMaser Key Science Programme.

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Correspondence to Willem A. Baan.

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

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Baan, W.A., An, T., Henkel, C. et al. H2O MegaMaser emission in NGC 4258 indicative of a periodic disc instability. Nat Astron 6, 976–983 (2022). https://doi.org/10.1038/s41550-022-01706-y

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