Electromagnetic Emission from Supermassive Binary Black Holes Approaching Merger

Understand

We present the first fully 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 3-d MHD 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/EUV 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.