science

From the article:

J1007+3540 lives inside a massive galaxy cluster filled with extremely hot gas. This environment creates enormous external pressure—far higher than what most radio galaxies experience. As the revived jets push outward, they are bent, squeezed, and distorted by the interaction with the dense medium.

Seems to me that it's not the black hole itself was turned off and on again, but rather that it's jet was suppressed by the colossal gravitational (?) pressure of the surrounding galactic core.