Analytical and Numerical Methods for Circumbinary Disk Dynamics. II. Inclined Disks
To gain insight into the dynamical influence of a supermassive black hole binary on a circumbinary accretion disk, we investigate the binary and viscous torque densities throughout such a disk, with emphasis on the final density distribution, particularly the size and stability of the central gap be...
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IOP Publishing
2025-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ada55e |
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| author | Michal Pirog Siddharth Mahesh Sean T. McWilliams |
| author_facet | Michal Pirog Siddharth Mahesh Sean T. McWilliams |
| author_sort | Michal Pirog |
| collection | DOAJ |
| description | To gain insight into the dynamical influence of a supermassive black hole binary on a circumbinary accretion disk, we investigate the binary and viscous torque densities throughout such a disk, with emphasis on the final density distribution, particularly the size and stability of the central gap between the binary and the inner edge of the disk. We limit ourselves to the simplified case of a massless viscous thin accretion disk under the influence of the gravitational potential from a binary system whose orbital plane is inclined relative to the disk. We employ two-dimensional Newtonian hydrodynamics simulations to examine the influence of two model parameters: the mass ratio of the binary and the inclination angle between the binary and the disk. We investigate their impact on the density and torque distribution. In our analytical approach, we consider the stability of epicycles induced by the perturbative effect of the asymmetric inclined binary gravitational potential on Keplerian circular orbits. Through our simulations, we observe that certain configurations never attain a quasi-steady state, where the density profile averaged over many orbits stabilizes. This instability occurs when the inclination is close to 45°. Furthermore, we identify configurations where there is never a persistent balance between the dynamical and viscous torque densities, as well as cases where the location of this balance oscillates or exhibits other time-dependent behavior over viscous timescales. These findings have implications for understanding both the expected gravitational-wave signal and electromagnetic counterparts from supermassive black hole binaries. |
| format | Article |
| id | doaj-art-70deb6ad49c345b2bfe2a76be4a6c68d |
| institution | Kabale University |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
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| series | The Astrophysical Journal |
| spelling | doaj-art-70deb6ad49c345b2bfe2a76be4a6c68d2025-02-07T09:07:43ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01980113010.3847/1538-4357/ada55eAnalytical and Numerical Methods for Circumbinary Disk Dynamics. II. Inclined DisksMichal Pirog0https://orcid.org/0000-0002-3164-5923Siddharth Mahesh1https://orcid.org/0000-0002-8340-614XSean T. McWilliams2https://orcid.org/0000-0003-2397-8290The Harriet L. Wilkes Honors College, Florida Atlantic University , Boca Raton, FL 33431, USA ; [email protected]; Department of Physics and Astronomy, West Virginia University , Morgantown, WV 26506, USA; Center for Gravitational Waves and Cosmology, West Virginia University , Chestnut Ridge Research Building, Morgantown, WV 26505, USADepartment of Physics and Astronomy, West Virginia University , Morgantown, WV 26506, USA; Center for Gravitational Waves and Cosmology, West Virginia University , Chestnut Ridge Research Building, Morgantown, WV 26505, USADepartment of Physics and Astronomy, West Virginia University , Morgantown, WV 26506, USA; Center for Gravitational Waves and Cosmology, West Virginia University , Chestnut Ridge Research Building, Morgantown, WV 26505, USATo gain insight into the dynamical influence of a supermassive black hole binary on a circumbinary accretion disk, we investigate the binary and viscous torque densities throughout such a disk, with emphasis on the final density distribution, particularly the size and stability of the central gap between the binary and the inner edge of the disk. We limit ourselves to the simplified case of a massless viscous thin accretion disk under the influence of the gravitational potential from a binary system whose orbital plane is inclined relative to the disk. We employ two-dimensional Newtonian hydrodynamics simulations to examine the influence of two model parameters: the mass ratio of the binary and the inclination angle between the binary and the disk. We investigate their impact on the density and torque distribution. In our analytical approach, we consider the stability of epicycles induced by the perturbative effect of the asymmetric inclined binary gravitational potential on Keplerian circular orbits. Through our simulations, we observe that certain configurations never attain a quasi-steady state, where the density profile averaged over many orbits stabilizes. This instability occurs when the inclination is close to 45°. Furthermore, we identify configurations where there is never a persistent balance between the dynamical and viscous torque densities, as well as cases where the location of this balance oscillates or exhibits other time-dependent behavior over viscous timescales. These findings have implications for understanding both the expected gravitational-wave signal and electromagnetic counterparts from supermassive black hole binaries.https://doi.org/10.3847/1538-4357/ada55eAstrophysical fluid dynamicsAccretionCircumstellar disksOrbital theoryOrbital resonancesComputational methods |
| spellingShingle | Michal Pirog Siddharth Mahesh Sean T. McWilliams Analytical and Numerical Methods for Circumbinary Disk Dynamics. II. Inclined Disks The Astrophysical Journal Astrophysical fluid dynamics Accretion Circumstellar disks Orbital theory Orbital resonances Computational methods |
| title | Analytical and Numerical Methods for Circumbinary Disk Dynamics. II. Inclined Disks |
| title_full | Analytical and Numerical Methods for Circumbinary Disk Dynamics. II. Inclined Disks |
| title_fullStr | Analytical and Numerical Methods for Circumbinary Disk Dynamics. II. Inclined Disks |
| title_full_unstemmed | Analytical and Numerical Methods for Circumbinary Disk Dynamics. II. Inclined Disks |
| title_short | Analytical and Numerical Methods for Circumbinary Disk Dynamics. II. Inclined Disks |
| title_sort | analytical and numerical methods for circumbinary disk dynamics ii inclined disks |
| topic | Astrophysical fluid dynamics Accretion Circumstellar disks Orbital theory Orbital resonances Computational methods |
| url | https://doi.org/10.3847/1538-4357/ada55e |
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