Abstract
We present the first relativistic prediction of the electromagnetic emission from the surrounding gas of a supermassive binary black hole system approaching merger. Using a ray-tracing code to post-process data from a general relativistic 3D magnetohydrodynamic simulation, we generate images and spectra, and analyze the viewing angle dependence of the light emitted. When the accretion rate is relatively high, the circumbinary disk, accretion streams, and mini-disks combine to emit light in the UV/extreme-UV bands. We posit a thermal Compton hard X-ray spectrum for coronal emission; at high accretion rates, it is almost entirely produced in the mini-disks, but at lower accretion rates it is the primary radiation mechanism in the mini-disks and accretion streams as well. Due to relativistic beaming and gravitational lensing, the angular distribution of the power radiated is strongly anisotropic, especially near the equatorial plane.
| Original language | English |
|---|---|
| Article number | 140 |
| Journal | Astrophysical Journal |
| Volume | 865 |
| Issue number | 2 |
| DOIs | |
| State | Published - Oct 1 2018 |
| Externally published | Yes |
Funding
S. D. was supported through the Center for Computational Relativity and Gravitation and Frontier in Gravitational Astrophysics program through RIT’s office of research. D. B., M. C., and V. M. received support from NSF grants AST-1028087, AST-1516150, PHY-1305730, PHY-1707946, OAC-1550436 and OAC-1516125. S. C. N. was supported by AST-1028087, AST-1515982 and OAC-1515969, and by an appointment to the NASA Postdoctoral Program at the Goddard Space Flight Center administered by USRA through a contract with NASA. J. H. K. was partially supported by NSF grants AST-1516299, PHYS-1707826 and OAC-1516247 and the Simons Foundation (grant 559794, JHU). V. M. also acknowledges partial support from AYA2015-66899-C2-1-P. Analysis and ray-tracing were performed on the Blue Waters system at the University of Illinois at Urbana-Champaign and its National Center for Supercomputing Applications, and the NewHorizons and BlueSky Clusters at Rochester Institute of Technology. The Blue Waters sustained-petascale computing project is supported by the National Science Foundation (awards OAC-0725070 and OAC-1238993) and the state of Illinois. This work is also part of the “Predicting the Transient Signals from Galactic Centers: Circumbinary Disks and Tidal Disruptions around Black Holes” PRAC allocation support by the National Science Foundation (award number OAC-151596). The NewHorizons and BlueSky Clusters were supported by NSF grant No. PHY-0722703, DMS-0820923, AST-1028087, and PHY-1229173. This work was performed in part at Aspen Center for Physics, which is supported by National Science Foundation grant PHY-1607611. The Blue Waters sustained-petascale computing project is supported by the National Science Foundation (awards OAC-0725070 and OAC-1238993) and the state of Illinois. This work is also part of the "Predicting the Transient Signals from Galactic Centers: Circumbinary Disks and Tidal Disruptions around Black Holes" PRAC allocation support by the National Science Foundation (award number OAC- 151596). The NewHorizons and BlueSky Clusters were supported by NSF grant No. PHY-0722703, DMS-0820923, AST-1028087, and PHY-1229173. This work was performed in part at Aspen Center for Physics, which is supported by National Science Foundation grant PHY-1607611.
Keywords
- accretion
- accretion disks
- black hole physics
- galaxies: nuclei
- magnetohydrodynamics (MHD)
- radiative transfer