I would note that the ripples are not concentric and diminish abruptly rather than with distance. I don't see yet how one can associate this image with a wave generator. I also don't see how you come up with a velocity for the "signal" being suggested.
ML/NJ
Yes.
" I just am not familiar with the use of the word ripple as a scientific term."
It's English and portrays waves through a fluid cross section very well. The fluid in this case is a gas embedded in a field of galaxies.
"I would note that the ripples are not concentric and diminish abruptly rather than with distance."
The entire assembly appears to have a 2.5Bly radius. The lack of concentricity is caused by spacial inhomogeneitiesous in the gas and resultant speed of sound variation, and rotational effects. There's no apparent dissipation, because the density peaks in the longitudinal waves are substantial and gravity will maintain that configuration. Pressure waves through gas regions generate stars.
The generating wave is a resultant og the BH's gas jet. If the ejecta moved at c, there would be 120 ripples. Since there are only ~5.5 ripples/radius, the ejecta, or speed of sound in the gas, is 0.05c.