Accretion columns
Laser Beams from the Accretion Columns Each of the two cameras now fires magical laser beams that show exactly where the light is coming from and how much weight it carries (this weight, or "amplitude", tells us which "sub-profile" contributes to the twinkling effect from there). It's like these invisible lasers give back what each beam said about their position: "I'm coming from here!
Technical definition
Accretion columns are the narrow channels of hot gas that falls onto a massive celestial object, such as a neutron star or black hole, and emits radiation.