Are Two Supermassive Black Holes on a Collision Course?

[Tom.G]

Well, not right away. It's about 10 000yrs in the future.

From: THE ASTROPHYSICAL JOURNAL LETTERS

The Unanticipated Phenomenology of the Blazar PKS 2131–021: A Unique Supermassive Black Hole Binary Candidate​

Popular version:
https://www.sciencealert.com/two-su...e-been-found-locked-in-the-tightest-orbit-yet

...two supermassive black holes are locked in an orbit so tight that they will collide with each other and form one much larger black hole in the relatively short time of just 10,000 years.
.
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...so fast are they moving that it takes just two Earth years for the two objects to complete a binary orbit, compared to Pluto's 248 years.

Full technical paper:
https://iopscience.iop.org/article/10.3847/2041-8213/ac504b

We report unique periodic radio flux density variations in the blazar PKS 2131−021, which strongly suggest an SMBHB <Super Massive Black Hole Binary> with an orbital separation of ∼0.001–0.01 pc. Our 45.1 yr radio light curve shows two epochs of strong sinusoidal variation with the same period and phase to within ≲2% and ∼10%, respectively, straddling a 20 yr period when this variation was absent.

Cheers,
Tom

 

[Vanadium 50]

Doggone it - that's when the plumber is coming!

 

[collinsmark]

Actually, there is a supermassive black hole (SMBH) merger predicted to happen quite soon, probably in 2022 (maybe as soon as a few months, but possible a few years, depending on the models.



Jiang et al. (2022; imminent merger of two SMBHs) - https://arxiv.org/pdf/2201.11633.pdf

Unfortunately, SMBH mergers are outside of the frequency range (too low of frequency) to be detected by our current generation gravitation wave detectors (e.g., LIGO). But I'm sure lots of conventional telescopes will be looking.