What evidence supports the existence of a black hole at the center of our galaxy?
A) We observe an extremely bright X-ray source at the center of our galaxy.
B) We can see gas falling into an accretion disk and past the event horizon of a black hole.
C) The motions of the gas and stars at the center indicate that it contains 4 million solar masses within a region only 3 light-years across.
D) We observe a large, dark object that absorbs all light at the center of our galaxy.
E) all of the above

Question

Quizplus · Accepted Answer

The motion of the gas and stars at the center of the galaxy indicate the presence of a very massive object. The measured mass of this object is consistent with a black hole. A, B, and D are also supporting evidence, but they alone do not definitively prove the existence of a black hole.

What Evidence Supports the Existence of a Black Hole at the Center