Final answer:
Astronomers observe black hole systems to enhance our understanding of physics, witness the effects of curved spacetime, and contribute to gravitational wave astronomy. They use observational evidence from binary star systems and the characteristics of supermassive black holes' accretion disks to establish the presence of these invisible yet influential cosmic entities.
Step-by-step explanation:
Astronomers continue to observe black hole systems to improve our understanding of these extraordinary objects and the fundamental physics that governs them. Observations provide vital evidence supporting the existence of black holes, which are predicted by Einstein's general theory of relativity and are known to warp or curve spacetime. Black holes offer insights into gravitational wave astronomy, as their interactions can produce gravitational waves detectable by instruments on Earth, enriching our knowledge of the universe's structure and the dynamics of massive objects.
Binary star systems are crucial for detecting and studying stellar-mass black holes. They are identified by the absence of the black hole's visual presence, the flickering X-ray emission from an accretion disk, and the interaction's effect on its companion star. These observations can reveal the mass of the invisible companion, affirming its black hole status if it is larger than 3 solar masses (Msun).
Additionally, at the centers of large galaxies, astronomers can find supermassive black holes with masses ranging from millions to billions of solar masses. The presence of these black holes is inferred based on the amount of mass packed into a very small volume, as normal objects could not account for such concentration. The surrounding hot accretion disk, visible via emissions and the movement of gas and dust, is one of the primary observational evidence for such black holes.