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AGN as potential factories for eccentric black hole mergers

Nature volume 603, pages 237–240 (2022)Cite this article

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Abstract

There is some weak evidence that the black hole merger named GW190521 had a non-zero eccentricity1,2. In addition, the masses of the component black holes exceeded the limit predicted by stellar evolution3. The large masses can be explained by successive mergers4,5, which may be efficient in gas disks surrounding active galactic nuclei, but it is difficult to maintain an eccentric orbit all the way to the merger, as basic physics would argue for circularization6. Here we show that active galactic nuclei disk environments can lead to an excess of eccentric mergers, if the interactions between single and binary black holes are frequent5 and occur with mutual inclinations of less than a few degrees. We further illustrate that this eccentric population has a different distribution of the inclination between the spin vectors of the black holes and their orbital angular momentum at merger7, referred to as the spin–orbit tilt, compared with the remaining circular mergers.

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Fig. 1: Illustration of an eccentric LIGO-Virgo source forming in an AGN disk.
Fig. 2: Merger probability.
Fig. 3: Dependence on orbital inclination.
Fig. 4: Distribution of orbital plane orientations.
Fig. 5: Eccentricity and gravitational-wave frequency distributions.

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The data that support the findings of this study are available from the corresponding author on reasonable request.

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References

  1. Gayathri, V. et al. Eccentricity estimate for black hole mergers with numerical relativity simulations. Nat. Astron. https://doi.org/10.1038/s41550-021-01568-w (2022).

  2. Romero-Shaw, I., Lasky, P. D., Thrane, E. & Calderón Bustillo, J. GW190521: orbital eccentricity and signatures of dynamical formation in a binary black hole merger signal. Astrophys. J. Lett. 903, L5 (2020).

    Article  ADS  CAS  Google Scholar 

  3. Abbott, R. et al. Properties and astrophysical implications of the 150M⊙ binary black hole merger GW190521. Astrophys. J. Lett. 900, L13 (2020).

    Article  ADS  CAS  Google Scholar 

  4. Yang, Y. et al. Hierarchical black hole mergers in active galactic nuclei. Phys. Rev. Lett. 123, 181101 (2019).

    Article  ADS  CAS  Google Scholar 

  5. Tagawa, H., Haiman, Z. & Kocsis, B. Formation and evolution of compact-object binaries in AGN disks. Astrophys. J. 898, 25 (2020).

    Article  ADS  CAS  Google Scholar 

  6. Peters, P. Gravitational radiation and the motion of two point masses. Phys. Rev. 136, B1224–B1232 (1964).

    Article  ADS  Google Scholar 

  7. Abbott, R. et al. GW190521: a binary black hole merger with a total mass of 150 M⊙. Phys. Rev. Lett. 125, 101102 (2020).

    Article  ADS  CAS  Google Scholar 

  8. Bartos, I., Kocsis, B., Haiman, Z. & Márka, S. Rapid and bright stellar-mass binary black hole mergers in active galactic nuclei. Astrophys. J. 835, 165 (2017).

    Article  ADS  Google Scholar 

  9. Levin, Y. Formation of massive stars and black holes in self-gravitating AGN discs, and gravitational waves in LISA band. Preprint at https://arxiv.org/abs/astro-ph/0307084 (2003).

  10. Stone, N. C., Metzger, B. D. & Haiman, Z. Assisted inspirals of stellar mass black holes embedded in AGN discs: solving the ‘final au problem’. Mon. Not. R. Astron. Soc. 464, 946–954 (2017).

    Article  ADS  CAS  Google Scholar 

  11. Cantiello, M., Jermyn, A. S. & Lin, D. N. C. Stellar evolution in AGN disks. Astrophys. J. 910, 94 (2021).

    Article  ADS  CAS  Google Scholar 

  12. McKernan, B., Ford, K. E. S., Lyra, W. & Perets, H. B. Intermediate mass black holes in AGN discs–I. Production and growth. Mon. Not. R. Astron. Soc. 425, 460–469 (2012).

    Article  ADS  Google Scholar 

  13. McKernan, B. et al. Constraining stellar-mass black hole mergers in AGN disks detectable with LIGO. Astrophys. J. 866, 66 (2018).

    Article  ADS  Google Scholar 

  14. Leigh, N. W. C. et al. On the rate of black hole binary mergers in galactic nuclei due to dynamical hardening. Mon. Not. R. Astron. Soc. 474, 5672–5683 (2018).

    Article  ADS  CAS  Google Scholar 

  15. Secunda, A. et al. Orbital migration of interacting stellar mass black holes in disks around supermassive black holes. Astrophys. J. 878, 85 (2019).

    Article  ADS  Google Scholar 

  16. Tagawa, H., Haiman, Z., Bartos, I. & Kocsis, B. Spin evolution of stellar-mass black hole binaries in active galactic nuclei. Astrophys. J. 899, 26 (2020).

    Article  ADS  Google Scholar 

  17. Kocsis, B., Gáspár, M. E. & Márka, S. Detection rate estimates of gravity waves emitted during parabolic encounters of stellar black holes in globular clusters. Astrophys. J. 648, 411–429 (2006).

    Article  ADS  CAS  Google Scholar 

  18. Rodriguez, C. L. et al. Post-Newtonian dynamics in dense star clusters: formation, masses, and merger rates of highly-eccentric black hole binaries. Phys. Rev. D 98, 123005 (2018).

    Article  ADS  CAS  Google Scholar 

  19. Samsing, J. Eccentric black hole mergers forming in globular clusters. Phys. Rev. D 97, 103014 (2018).

    Article  ADS  CAS  Google Scholar 

  20. Graham, M. J. et al. Candidate electromagnetic counterpart to the binary black hole merger gravitational-wave event S190521g. Phys. Rev. Lett. 124, 251102 (2020).

    Article  ADS  CAS  Google Scholar 

  21. Blanchet, L. Gravitational radiation from post-Newtonian sources and inspiralling compact binaries. Living Rev. Relativ. 17, 2 (2014).

    Article  ADS  Google Scholar 

  22. Samsing, J. & D’Orazio, D. J. Black hole mergers from globular clusters observable by LISA I: eccentric sources originating from relativistic N-body dynamics. Mon. Not. R. Astron. Soc. 481, 5445–5450 (2018).

    Article  ADS  CAS  Google Scholar 

  23. Monaghan, J. J. A statistical theory of the disruption of three-body systems — II. High angular momentum. Mon. Not. R. Astron. Soc. 177, 583–594 (1976).

    Article  ADS  Google Scholar 

  24. Valtonen, M. & Karttunen, H. The Three-Body Problem (Cambridge Univ. Press, 2006).

  25. Stone, N. C. & Leigh, N. W. C. A statistical solution to the chaotic, non-hierarchical three-body problem. Nature 576, 406–410 (2019).

    Article  ADS  CAS  Google Scholar 

  26. Thompson, T. A., Quataert, E. & Murray, N. Radiation pressure-supported starburst disks and active galactic nucleus fueling. Astrophys. J. 630, 167–185 (2005).

    Article  ADS  Google Scholar 

  27. Rodriguez, C. L., Zevin, M., Pankow, C., Kalogera, V. & Rasio, F. A. Illuminating black hole binary formation channels with spins in advanced LIGO. Astrophys. J. 832, L2 (2016).

    Article  ADS  Google Scholar 

  28. Ostriker, E. C. Dynamical friction in a gaseous medium. Astrophys. J. 513, 252–258 (1999).

    Article  ADS  Google Scholar 

  29. Kim, H. & Kim, W.-T. Dynamical friction of a circular-orbit perturber in a gaseous medium. Astrophys. J. 665, 432–444 (2007).

    Article  ADS  Google Scholar 

  30. Samsing, J., MacLeod, M. & Ramirez-Ruiz, E. The formation of eccentric compact binary inspirals and the role of gravitational wave emission in binary-single stellar encounters. Astrophys. J. 784, 71 (2014).

    Article  ADS  Google Scholar 

  31. Samsing, J., MacLeod, M. & Ramirez-Ruiz, E. Formation of tidal captures and gravitational wave inspirals in binary-single interactions. Astrophys. J. 846, 36 (2017).

    Article  ADS  Google Scholar 

  32. Samsing, J., MacLeod, M. & Ramirez-Ruiz, E. Dissipative evolution of unequal-mass binary–single interactions and its relevance to gravitational-wave detections. Astrophys. J. 853, 140 (2018).

    Article  ADS  Google Scholar 

  33. Heggie, D. C. Binary evolution in stellar dynamics. Mon. Not. R. Astron. Soc. 173, 729–787 (1975).

    Article  ADS  Google Scholar 

  34. Samsing, J., Askar, A. & Giersz, M. MOCCA-SURVEY database. I. Eccentric black hole mergers during binary–single interactions in globular clusters. Astrophys. J. 855, 124 (2018).

    Article  ADS  Google Scholar 

  35. Gondán, L. & Kocsis, B. Measurement accuracy of inspiraling eccentric neutron star and black hole binaries using gravitational waves. Astrophys. J. 871, 178 (2019).

    Article  ADS  Google Scholar 

  36. Zevin, M., Samsing, J., Rodriguez, C., Haster, C.-J. & Ramirez-Ruiz, E. Eccentric black hole mergers in dense star clusters: the role of binary–binary encounters. Astrophys. J. 871, 91 (2019).

    Article  ADS  Google Scholar 

  37. Li, Y.-P., Dempsey, A. M., Li, S., Li, H. & Li, J. Orbital evolution of binary black holes in active galactic nucleus disks: a disk channel for binary black hole mergers? Astrophys. J. 911, 124 (2021).

    Article  ADS  CAS  Google Scholar 

  38. Samsing, J., Hamers, A. S. & Tyles, J. G. Effect of distant encounters on black hole binaries in globular clusters: systematic increase of in-cluster mergers in the LISA band. Phys. Rev. D 100, 043010 (2019).

    Article  ADS  CAS  Google Scholar 

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Acknowledgements

We are grateful to N. Bose, K. Holley-Bockelmann, A. Pai, M. Zevin and M. Safarzadeh for their useful suggestions. J.S. is supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 844629. D.J.D. received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 101029157 and through Villum Fonden grant no. 29466. I.B. acknowledges the support of the Alfred P. Sloan Foundation and NSF grants PHY-1911796 and PHY-2110060. H.T. is financially supported by the Grants-in-Aid for Basic Research by the Ministry of Education, Science and Culture of Japan (17H01102, 17H06360) and the Japan Society for the Promotion of Science (JSPS) KAKENHI grant number JP21J00794. N.W.C.L. acknowledges the support of a Fondecyt Iniciación grant 11180005, the financial support from Millenium Nucleus NCN19-058 (TITANs) and the BASAL Centro de Excelencia en Astrofisica y Tecnologias Afines (CATA) grant CATA AFB170002 along with ANID BASAL projects ACE210002 and FB210003. Z.H. acknowledges support from NASA grant NNX15AB19G and NSF grants AST-1715661 and AST-2006176. B.L. gratefully acknowledges support from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement no. 847523 ‘INTERACTIONS’. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme ERC-2014-STG under grant agreement no. 638435 (GalNUC) to B.K. M.E.P. gratefully acknowledges support from the Independent Research Fund Denmark (DFF) via grant no. DFF 8021-00400B.

Author information

Authors and Affiliations

  1. Niels Bohr International Academy, Niels Bohr Institute, Copenhagen, Denmark

    J. Samsing, D. J. D’Orazio, B. Liu & M. E. Pessah

  2. Department of Physics, University of Florida, Gainesville, FL, USA

    I. Bartos

  3. Department of Astronomy, Columbia University, New York, NY, USA

    Z. Haiman

  4. Rudolf Peierls Centre for Theoretical Physics, Clarendon Laboratory, Oxford, UK

    B. Kocsis

  5. St Hugh’s College, Oxford, UK

    B. Kocsis

  6. Departamento de Astronomía, Facultad Ciencias Físicas y Matemáticas, Universidad de Concepción, Concepción, Chile

    N. W. C. Leigh

  7. Department of Astrophysics, American Museum of Natural History, New York, NY, USA

    N. W. C. Leigh

  8. Astronomical Institute, Tohoku University, Sendai, Miyagi, Japan

    H. Tagawa

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  1. J. Samsing
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Contributions

J.S. led the work, carried out the simulations and calculations, and wrote the initial manuscript together with I.B. and D.J.D. The remaining authors, Z.H., B.K., N.W.C.L., B.L., M.E.P. and H.T., all contributed equally to the intellectual development of the ideas and the preparation of the final manuscript.

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Correspondence to J. Samsing.

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Samsing, J., Bartos, I., D’Orazio, D.J. et al. AGN as potential factories for eccentric black hole mergers. Nature 603, 237–240 (2022). https://doi.org/10.1038/s41586-021-04333-1

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