When we see X- rays from an accretion disk in a binary system, we can't immediately tell whether the accretion disk surrounds a neutron star or a black hole. Suppose we then observe each of the following phenomena in this system. Which one would rule out the possibility of a black hole?
A)bright X- ray emission that varies on a time scale of a few hours
B)intense X- ray bursts
C)visible and ultraviolet light from the companion star
D)spectral lines from the companion star that alternately shift to shorter and longer wavelengths

Question

Quizplus · Accepted Answer

Intense X-ray bursts are characteristic of neutron star systems, not black holes. These bursts are caused by thermonuclear explosions on the surface of the neutron star, a phenomenon that cannot occur in a black hole because black holes do not have a solid surface where material can accumulate and ignite in a nuclear explosion.

When We See X- Rays from an Accretion Disk in a Binary