What process causes the material approaching a black hole to shine brightly, often in X-ray light?

Answer

Particles in the accretion disc smashing into each other violently

Material falling toward a black hole forms a swirling accretion disc; particles collide with such violence that their charges shake intensely, heating the disc to extremes that cause it to shine brightly.

What process causes the material approaching a black hole to shine brightly, often in X-ray light?

#Videos

How Do Stars Produce Light? - Physics Frontier - YouTube

lightastronomystarradiation