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Abstract Supermassive binary black holes are a key target for the future Laser Interferometer Space Antenna and excellent multimessenger sources across the electromagnetic (EM) spectrum. However, unique features of their EM emission that are needed to distinguish them from single supermassive black holes are still being established. Here, we conduct the first magnetohydrodynamic simulation of disk accretion onto equal-mass, nonspinning, eccentric binary black holes in full general relativity, incorporating synchrotron radiation transport through the dual jet in postprocessing. Focusing on a binary in the strong-field dynamical spacetime regime with eccentricitye= 0.3 as a point of principle, we show that the total accretion rate exhibits periodicity on the binary orbital period. We also show, for the first time, that this periodicity is reflected in the jet Poynting luminosity and the optically thin synchrotron emission from the jet base. Furthermore, we find a distinct EM signature for eccentric binaries: they spend more time in a low emission state (at apocenter) and less in a high state (at pericenter). Additionally, we find that the eccentric binary quasiperiodic gravitational-wave (GW) bursts are coincident with the bursts in Poynting luminosity and synchrotron emission. Finally, we discuss how multimessenger EM and GW observations of these systems can help probe plasma physics in their jet.
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Minidisc influence on flow variability in accreting spinning black hole binaries: simulations in full general relativity
ABSTRACT We perform magnetohydrodynamic simulations of accreting, equal-mass binary black holes in full general relativity focusing on the effect of spin and minidiscs on the accretion rate and Poynting luminosity variability. We report on the structure of the minidiscs and periodicities in the mass of the minidiscs, mass accretion rates, and Poynting luminosity. The accretion rate exhibits a quasi-periodic behaviour related to the orbital frequency of the binary in all systems that we study, but the amplitude of this modulation is dependent on the existence of persistent minidiscs. In particular, systems that are found to produce persistent minidiscs have a much weaker modulation of the mass accretion rate, indicating that minidiscs can increase the inflow time of matter on to the black holes, and dampen out the quasi-periodic behaviour. This finding has potential consequences for binaries at greater separations where minidiscs can be much larger and may dampen out the periodicities significantly.
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- PAR ID:
- 10423755
- Date Published:
- Journal Name:
- Monthly Notices of the Royal Astronomical Society
- Volume:
- 520
- Issue:
- 1
- ISSN:
- 0035-8711
- Page Range / eLocation ID:
- 392 to 401
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1093/mnras/stad091
